This document is obsolete. Please
refer to RFC 8011.
Network Working Group T. Hastings, Editor Request for Comments: 2911 R. Herriot Obsoletes: 2566 Xerox Corporation Category: Standards Track R. deBry Utah Valley State College S. Isaacson Novell, Inc. P. Powell Astart Technologies September 2000
Internet Printing Protocol/1.1: Model and Semantics
Status of this Memo
This document specifies an Internet standards track protocol for the Internet community, and requests discussion and suggestions for improvements. Please refer to the current edition of the "Internet Official Protocol Standards" (STD 1) for the standardization state and status of this protocol. Distribution of this memo is unlimited.
Copyright Notice
Copyright (C) The Internet Society (2000). All Rights Reserved.
Abstract
This document is one of a set of documents, which together describe all aspects of a new Internet Printing Protocol (IPP). IPP is an application level protocol that can be used for distributed printing using Internet tools and technologies. This document describes a simplified model consisting of abstract objects, their attributes, and their operations that is independent of encoding and transport. The model consists of a Printer and a Job object. A Job optionally supports multiple documents. IPP 1.1 semantics allow end-users and operators to query printer capabilities, submit print jobs, inquire about the status of print jobs and printers, cancel, hold, release, and restart print jobs. IPP 1.1 semantics allow operators to pause, resume, and purge (jobs from) Printer objects. This document also addresses security, internationalization, and directory issues.
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The full set of IPP documents includes:
Design Goals for an Internet Printing Protocol [RFC2567] Rationale for the Structure and Model and Protocol for the Internet Printing Protocol [RFC2568] Internet Printing Protocol/1.1: Model and Semantics (this document) Internet Printing Protocol/1.1: Encoding and Transport [RFC2910] Internet Printing Protocol/1.1: Implementer's Guide [IPP-IIG] Mapping between LPD and IPP Protocols [RFC2569]
The "Design Goals for an Internet Printing Protocol" document takes a broad look at distributed printing functionality, and it enumerates real-life scenarios that help to clarify the features that need to be included in a printing protocol for the Internet. It identifies requirements for three types of users: end users, operators, and administrators. It calls out a subset of end user requirements that are satisfied in IPP/1.0. A few OPTIONAL operator operations have been added to IPP/1.1.
The "Rationale for the Structure and Model and Protocol for the Internet Printing Protocol" document describes IPP from a high level view, defines a roadmap for the various documents that form the suite of IPP specification documents, and gives background and rationale for the IETF working group's major decisions.
The "Internet Printing Protocol/1.1: Encoding and Transport" document is a formal mapping of the abstract operations and attributes defined in the model document onto HTTP/1.1 [RFC2616]. It defines the encoding rules for a new Internet MIME media type called "application/ipp". This document also defines the rules for transporting over HTTP a message body whose Content-Type is "application/ipp". This document defines a new scheme named 'ipp' for identifying IPP printers and jobs.
The "Internet Printing Protocol/1.1: Implementer's Guide" document gives insight and advice to implementers of IPP clients and IPP objects. It is intended to help them understand IPP/1.1 and some of the considerations that may assist them in the design of their client and/or IPP object implementations. For example, a typical order of processing requests is given, including error checking. Motivation for some of the specification decisions is also included.
The "Mapping between LPD and IPP Protocols" document gives some advice to implementers of gateways between IPP and LPD (Line Printer Daemon) implementations.
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The Internet Printing Protocol (IPP) is an application level protocol that can be used for distributed printing using Internet tools and technologies. IPP version 1.1 (IPP/1.1) focuses primarily on end user functionality with a few administrative operations included. This document is just one of a suite of documents that fully define IPP. The full set of IPP documents includes:
Design Goals for an Internet Printing Protocol [RFC2567] Rationale for the Structure and Model and Protocol for the Internet Printing Protocol [RFC2568] Internet Printing Protocol/1.1: Model and Semantics (this document) Internet Printing Protocol/1.1: Encoding and Transport [RFC2910] Internet Printing Protocol/1.1: Implementer's Guide [IPP-IIG] Mapping between LPD and IPP Protocols [RFC2569]
Anyone reading these documents for the first time is strongly encouraged to read the IPP documents in the above order.
This document is laid out as follows:
- The rest of Section 1 is an introduction to the IPP simplified model for distributed printing. - Section 2 introduces the object types covered in the model with their basic behaviors, attributes, and interactions. - Section 3 defines the operations included in IPP/1.1. IPP operations are synchronous, therefore, for each operation, there is a both request and a response. - Section 4 defines the attributes (and their syntaxes) that are used in the model. - Sections 5 - 6 summarizes the implementation conformance requirements for objects that support the protocol and IANA considerations, respectively. - Sections 7 - 11 cover the Internationalization and Security considerations as well as References, Author contact information, and Formats for Registration Proposals. - Sections 12 - 14 are appendices that cover Terminology, Status Codes and Messages, and "media" keyword values.
Note: This document uses terms such as "attributes", "keywords", and "support". These terms have special meaning and are defined in the model terminology section 12.2. Capitalized terms, such as MUST, MUST NOT, REQUIRED, SHOULD, SHOULD NOT, MAY, NEED NOT, and OPTIONAL, have special meaning relating to conformance. These terms are defined in section 12.1 on conformance terminology, most of which is taken from RFC 2119 [RFC2119].
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- Section 15 is an appendix that helps to clarify the effects of interactions between related attributes and their values. - Section 16 is an appendix that enumerates the subset of Printer attributes that form a generic directory schema. These attributes are useful when registering a Printer so that a client can find the Printer not just by name, but by filtered searches as well. - Section 17 is an appendix summarizing the additions and changes from the IPP/1.0 "Model and Semantics" document [RFC2566] to make this IPP/1.1 document. - Section 18 is the full copyright notice.
In order to achieve its goal of realizing a workable printing protocol for the Internet, the Internet Printing Protocol (IPP) is based on a simplified printing model that abstracts the many components of real world printing solutions. The Internet is a distributed computing environment where requesters of print services (clients, applications, printer drivers, etc.) cooperate and interact with print service providers. This model and semantics document describes a simple, abstract model for IPP even though the underlying configurations may be complex "n-tier" client/server systems. An important simplifying step in the IPP model is to expose only the key objects and interfaces required for printing. The model described in this model document does not include features, interfaces, and relationships that are beyond the scope of the first version of IPP (IPP/1.1). IPP/1.1 incorporates many of the relevant ideas and lessons learned from other specification and development efforts [HTPP] [ISO10175] [LDPA] [P1387.4] [PSIS] [RFC1179] [SWP]. IPP is heavily influenced by the printing model introduced in the Document Printing Application (DPA) [ISO10175] standard. Although DPA specifies both end user and administrative features, IPP version 1.1 (IPP/1.1) focuses primarily on end user functionality with a few additional OPTIONAL operator operations.
The IPP/1.1 model encapsulates the important components of distributed printing into two object types:
Each object type has an associated set of operations (see section 3) and attributes (see section 4).
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It is important, however, to understand that in real system implementations (which lie underneath the abstracted IPP/1.1 model), there are other components of a print service which are not explicitly defined in the IPP/1.1 model. The following figure illustrates where IPP/1.1 fits with respect to these other components.
+--------------+ | Application | o +. . . . . . . | \|/ | Spooler | / \ +. . . . . . . | +---------+ End-User | Print Driver |---| File | +-----------+ +-----+ +------+-------+ +----+----+ | Browser | | GUI | | | +-----+-----+ +--+--+ | | | | | | | +---+------------+---+ | N D S | | IPP Client |------------+ O I E | +---------+----------+ T R C | | I E U | F C R -------------- Transport ------------------ I T I C O T | --+ A R Y +--------+--------+ | T Y | IPP Server | | I +--------+--------+ | O | | N +-----------------+ | IPP Printer | Print Service | | +-----------------+ | | --+ +-----------------+ | Output Device(s)| +-----------------+
An IPP Printer object encapsulates the functions normally associated with physical output devices along with the spooling, scheduling and multiple device management functions often associated with a print server. Printer objects are optionally registered as entries in a directory where end users find and select them based on some sort of filtered and context based searching mechanism (see section 16). The directory is used to store relatively static information about the Printer, allowing end users to search for and find Printers that match their search criteria, for example: name, context, printer capabilities, etc. The more dynamic information, such as state, currently loaded and ready media, number of jobs at the Printer,
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errors, warnings, and so forth, is directly associated with the Printer object itself rather than with the entry in the directory which only represents the Printer object.
IPP clients implement the IPP protocol on the client side and give end users (or programs running on behalf of end users) the ability to query Printer objects and submit and manage print jobs. An IPP server is just that part of the Printer object that implements the server-side protocol. The rest of the Printer object implements (or gateways into) the application semantics of the print service itself. The Printer objects may be embedded in an output device or may be implemented on a host on the network that communicates with an output device.
When a job is submitted to the Printer object and the Printer object validates the attributes in the submission request, the Printer object creates a new Job object. The end user then interacts with this new Job object to query its status and monitor the progress of the job. An end user can also cancel their print jobs by using the Job object's Cancel-Job operation. An end-user can also hold, release, and restart their print jobs using the Job object's OPTIONAL Hold-Job, Release-Job, and Restart-Job operations, if implemented.
A privileged operator or administrator of a Printer object can cancel, hold, release, and restart any user's job using the REQUIRED Cancel-Job and the OPTIONAL Hold-Job, Release-Job, and Restart-Job operations. In additional privileged operator or administrator of a Printer object can pause, resume, or purge (jobs from) a Printer object using the OPTIONAL Pause-Printer, Resume-Printer, and Purge- Jobs operations, if implemented.
The notification service is out of scope for this IPP/1.1 document, but using such a notification service, the end user is able to register for and receive Printer specific and Job specific events. An end user can query the status of Printer objects and can follow the progress of Job objects by polling using the Get-Printer- Attributes, Get-Jobs, and Get-Job-Attributes operations.
The IPP/1.1 model introduces objects of type Printer and Job. Each type of object models relevant aspects of a real-world entity such as a real printer or real print job. Each object type is defined as a set of possible attributes that may be supported by instances of that object type. For each object (instance), the actual set of supported attributes and values describe a specific implementation. The object's attributes and values describe its state, capabilities, realizable features, job processing functions, and default behaviors
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and characteristics. For example, the Printer object type is defined as a set of attributes that each Printer object potentially supports. In the same manner, the Job object type is defined as a set of attributes that are potentially supported by each Job object.
Each attribute included in the set of attributes defining an object type is labeled as:
- "REQUIRED": each object MUST support the attribute. - "RECOMMENDED": each object SHOULD support the attribute. - "OPTIONAL": each object MAY support the attribute.
Some definitions of attribute values indicate that an object MUST or SHOULD support the value; otherwise, support of the value is OPTIONAL.
However, if an implementation supports an attribute, it MUST support at least one of the possible values for that attribute.
The major component of the IPP/1.1 model is the Printer object. A Printer object implements the server-side of the IPP/1.1 protocol. Using the protocol, end users may query the attributes of the Printer object and submit print jobs to the Printer object. The actual implementation components behind the Printer abstraction may take on different forms and different configurations. However, the model abstraction allows the details of the configuration of real components to remain opaque to the end user. Section 3 describes each of the Printer operations in detail.
The capabilities and state of a Printer object are described by its attributes. Printer attributes are divided into two groups:
- "job-template" attributes: These attributes describe supported job processing capabilities and defaults for the Printer object. (See section 4.2) - "printer-description" attributes: These attributes describe the Printer object's identification, state, location, references to other sources of information about the Printer object, etc. (see section 4.4)
Since a Printer object is an abstraction of a generic document output device and print service provider, a Printer object could be used to represent any real or virtual device with semantics consistent with the Printer object, such as a fax device, an imager, or even a CD writer.
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Some examples of configurations supporting a Printer object include:
1) An output device with no spooling capabilities 2) An output device with a built-in spooler 3) A print server supporting IPP with one or more associated output devices 3a) The associated output devices may or may not be capable of spooling jobs 3b) The associated output devices may or may not support IPP
The following figures show some examples of how Printer objects can be realized on top of various distributed printing configurations. The embedded case below represents configurations 1 and 2. The hosted and fan-out figures below represent configurations 3a and 3b.
In this document the term "client" refers to a software entity that sends IPP operation requests to an IPP Printer object and accepts IPP operation responses. A client MAY be:
1. contained within software controlled by an end user, e.g. activated by the "Print" menu item in an application or
2. the print server component that sends IPP requests to either an output device or another "downstream" print server.
The term "IPP Printer" is a network entity that accepts IPP operation requests and returns IPP operation responses. As such, an IPP object MAY be:
1. an (embedded) device component that accepts IPP requests and controls the device or
2. a component of a print server that accepts IPP requests (where the print server controls one or more networked devices using IPP or other protocols).
Legend:
##### indicates a Printer object which is either embedded in an output device or is hosted in a server. The Printer object might or might not be capable of queuing/spooling.
any indicates any network protocol or direct connect, including IPP
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A Job object is used to model a print job. A Job object contains documents. The information required to create a Job object is sent in a create request from the end user via an IPP Client to the Printer object. The Printer object validates the create request, and if the Printer object accepts the request, the Printer object creates the new Job object. Section 3 describes each of the Job operations in detail.
The characteristics and state of a Job object are described by its attributes. Job attributes are grouped into two groups as follows:
- "job-template" attributes: These attributes can be supplied by the client or end user and include job processing instructions which are intended to override any Printer object defaults and/or instructions embedded within the document data. (See section 4.2)
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- "job-description" attributes: These attributes describe the Job object's identification, state, size, etc. The client supplies some of these attributes, and the Printer object generates others. (See section 4.3)
An implementation MUST support at least one document per Job object. An implementation MAY support multiple documents per Job object. A document is either:
- a stream of document data in a format supported by the Printer object (typically a Page Description Language - PDL), or - a reference to such a stream of document data
In IPP/1.1, a document is not modeled as an IPP object, therefore it has no object identifier or associated attributes. All job processing instructions are modeled as Job object attributes. These attributes are called Job Template attributes and they apply equally to all documents within a Job object.
IPP objects have relationships that are maintained persistently along with the persistent storage of the object attributes.
A Printer object can represent either one or more physical output devices or a logical device which "processes" jobs but never actually uses a physical output device to put marks on paper. Examples of logical devices include a Web page publisher or a gateway into an online document archive or repository. A Printer object contains zero or more Job objects.
A Job object is contained by exactly one Printer object, however the identical document data associated with a Job object could be sent to either the same or a different Printer object. In this case, a second Job object would be created which would be almost identical to the first Job object, however it would have new (different) Job object identifiers (see section 2.4).
A Job object is either empty (before any documents have been added) or contains one or more documents. If the contained document is a stream of document data, that stream can be contained in only one document. However, there can be identical copies of the stream in other documents in the same or different Job objects. If the contained document is just a reference to a stream of document data, other documents (in the same or different Job object(s)) may contain the same reference.
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All Printer and Job objects are identified by a Uniform Resource Identifier (URI) [RFC2396] so that they can be persistently and unambiguously referenced. Since every URL is a specialized form of a URI, even though the more generic term URI is used throughout the rest of this document, its usage is intended to cover the more specific notion of URL as well.
An administrator configures Printer objects to either support or not support authentication and/or message privacy using Transport Layer Security (TLS) [RFC2246] (the mechanism for security configuration is outside the scope of this IPP/1.1 document). In some situations, both types of connections (both authenticated and unauthenticated) can be established using a single communication channel that has some sort of negotiation mechanism. In other situations, multiple communication channels are used, one for each type of security configuration. Section 8 provides a full description of all security considerations and configurations.
If a Printer object supports more than one communication channel, some or all of those channels might support and/or require different security mechanisms. In such cases, an administrator could expose the simultaneous support for these multiple communication channels as multiple URIs for a single Printer object where each URI represents one of the communication channels to the Printer object. To support this flexibility, the IPP Printer object type defines a multi-valued identification attribute called the "printer-uri-supported" attribute. It MUST contain at least one URI. It MAY contain more than one URI. That is, every Printer object will have at least one URI that identifies at least one communication channel to the Printer object, but it may have more than one URI where each URI identifies a different communication channel to the Printer object. The "printer-uri-supported" attribute has two companion attributes, the "uri-security-supported" attribute and the "uri-authentication- supported". Both have the same cardinality as "printer-uri- supported". The purpose of the "uri-security-supported" attribute is to indicate the security mechanisms (if any) used for each URI listed in "printer-uri-supported". The purpose of the "uri-authentication- supported" attribute is to indicate the authentication mechanisms (if any) used for each URI listed in "printer-uri-supported". These three attributes are fully described in sections 4.4.1, 4.4.2, and 4.4.3.
When a job is submitted to the Printer object via a create request, the client supplies only a single Printer object URI. The client supplied Printer object URI MUST be one of the values in the "printer-uri-supported" Printer attribute.
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IPP/1.1 does not specify how the client obtains the client supplied URI, but it is RECOMMENDED that a Printer object be registered as an entry in a directory service. End-users and programs can then interrogate the directory searching for Printers. Section 16 defines a generic schema for Printer object entries in the directory service and describes how the entry acts as a bridge to the actual IPP Printer object. The entry in the directory that represents the IPP Printer object includes the possibly many URIs for that Printer object as values in one its attributes.
When a client submits a create request to the Printer object, the Printer object validates the request and creates a new Job object. The Printer object assigns the new Job object a URI which is stored in the "job-uri" Job attribute. This URI is then used by clients as the target for subsequent Job operations. The Printer object generates a Job URI based on its configured security policy and the URI used by the client in the create request.
For example, consider a Printer object that supports both a communication channel secured by the use of SSL3 (using HTTP over SSL3 with an "https" schemed URI) and another open communication channel that is not secured with SSL3 (using a simple "http" schemed URI). If a client were to submit a job using the secure URI, the Printer object would assign the new Job object a secure URI as well. If a client were to submit a job using the open-channel URI, the Printer would assign the new Job object an open-channel URI.
In addition, the Printer object also populates the Job object's "job-printer-uri" attribute. This is a reference back to the Printer object that created the Job object. If a client only has access to a Job object's "job-uri" identifier, the client can query the Job's "job-printer-uri" attribute in order to determine which Printer object created the Job object. If the Printer object supports more than one URI, the Printer object picks the one URI supplied by the client when creating the job to build the value for and to populate the Job's "job-printer-uri" attribute.
Allowing Job objects to have URIs allows for flexibility and scalability. For example, in some implementations, the Printer object might create Jobs that are processed in the same local environment as the Printer object itself. In this case, the Job URI might just be a composition of the Printer's URI and some unique component for the Job object, such as the unique 32-bit positive integer mentioned later in this paragraph. In other implementations, the Printer object might be a central clearing-house for validating all Job object creation requests, but the Job object itself might be created in some environment that is remote from the Printer object. In this case, the Job object's URI may have no physical-location
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relationship at all to the Printer object's URI. Again, the fact that Job objects have URIs allows for flexibility and scalability, however, many existing printing systems have local models or interface constraints that force print jobs to be identified using only a 32-bit positive integer rather than an independent URI. This numeric Job ID is only unique within the context of the Printer object to which the create request was originally submitted. Therefore, in order to allow both types of client access to IPP Job objects (either by Job URI or by numeric Job ID), when the Printer object successfully processes a create request and creates a new Job object, the Printer object MUST generate both a Job URI and a Job ID. The Job ID (stored in the "job-id" attribute) only has meaning in the context of the Printer object to which the create request was originally submitted. This requirement to support both Job URIs and Job IDs allows all types of clients to access Printer objects and Job objects no matter the local constraints imposed on the client implementation.
In addition to identifiers, Printer objects and Job objects have names ("printer-name" and "job-name"). An object name NEED NOT be unique across all instances of all objects. A Printer object's name is chosen and set by an administrator through some mechanism outside the scope of this IPP/1.1 document. A Job object's name is optionally chosen and supplied by the IPP client submitting the job. If the client does not supply a Job object name, the Printer object generates a name for the new Job object. In all cases, the name only has local meaning.
To summarize:
- Each Printer object is identified with one or more URIs. The Printer's "printer-uri-supported" attribute contains the URI(s). - The Printer object's "uri-security-supported" attribute identifies the communication channel security protocols that may or may not have been configured for the various Printer object URIs (e.g., 'tls' or 'none'). - The Printer object's "uri-authentication-supported" attribute identifies the authentication mechanisms that may or may not have been configured for the various Printer object URIs (e.g., 'digest' or 'none'). - Each Job object is identified with a Job URI. The Job's "job- uri" attribute contains the URI. - Each Job object is also identified with Job ID which is a 32- bit, positive integer. The Job's "job-id" attribute contains the Job ID. The Job ID is only unique within the context of the Printer object which created the Job object.
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- Each Job object has a "job-printer-uri" attribute which contains the URI of the Printer object that was used to create the Job object. This attribute is used to determine the Printer object that created a Job object when given only the URI for the Job object. This linkage is necessary to determine the languages, charsets, and operations which are supported on that Job (the basis for such support comes from the creating Printer object). - Each Printer object has a name (which is not necessarily unique). The administrator chooses and sets this name through some mechanism outside the scope of this IPP/1.1 document. The Printer object's "printer-name" attribute contains the name. - Each Job object has a name (which is not necessarily unique). The client optionally supplies this name in the create request. If the client does not supply this name, the Printer object generates a name for the Job object. The Job object's "job-name" attribute contains the name.
IPP objects support operations. An operation consists of a request and a response. When a client communicates with an IPP object, the client issues an operation request to the URI for that object. Operation requests and responses have parameters that identify the operation. Operations also have attributes that affect the run-time characteristics of the operation (the intended target, localization information, etc.). These operation-specific attributes are called operation attributes (as compared to object attributes such as Printer object attributes or Job object attributes). Each request carries along with it any operation attributes, object attributes, and/or document data required to perform the operation. Each request requires a response from the object. Each response indicates success or failure of the operation with a status code as a response parameter. The response contains any operation attributes, object attributes, and/or status messages generated during the execution of the operation request.
This section describes the semantics of the IPP operations, both requests and responses, in terms of the parameters, attributes, and other data associated with each operation.
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The Send-Document and Send-URI Job operations are used to add a new document to an existing multi-document Job object created using the Create-Job operation.
All IPP operations require some common parameters and operation attributes. These common elements and their semantic characteristics are defined and described in more detail in the following sections.
Every operation request contains the following REQUIRED parameters:
- a "version-number", - an "operation-id", - a "request-id", and - the attributes that are REQUIRED for that type of request.
Every operation response contains the following REQUIRED parameters:
- a "version-number", - a "status-code", - the "request-id" that was supplied in the corresponding request, and - the attributes that are REQUIRED for that type of response.
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The "Encoding and Transport" document [RFC2910] defines special rules for the encoding of these parameters. All other operation elements are represented using the more generic encoding rules for attributes and groups of attributes.
Each IPP operation request includes an identifying "operation-id" value. Valid values are defined in the "operations-supported" Printer attribute section (see section 4.4.15). The client specifies which operation is being requested by supplying the correct "operation-id" value.
In addition, every invocation of an operation is identified by a "request-id" value. For each request, the client chooses the "request-id" which MUST be an integer (possibly unique depending on client requirements) in the range from 1 to 2**31 - 1 (inclusive). This "request-id" allows clients to manage multiple outstanding requests. The receiving IPP object copies all 32-bits of the client- supplied "request-id" attribute into the response so that the client can match the response with the correct outstanding request, even if the "request-id" is out of range. If the request is terminated before the complete "request-id" is received, the IPP object rejects the request and returns a response with a "request-id" of 0.
Note: In some cases, the transport protocol underneath IPP might be a connection oriented protocol that would make it impossible for a client to receive responses in any order other than the order in which the corresponding requests were sent. In such cases, the "request-id" attribute would not be essential for correct protocol operation. However, in other mappings, the operation responses can come back in any order. In these cases, the "request-id" would be essential.
Operation requests and responses are both composed of groups of attributes and/or document data. The attributes groups are:
- Operation Attributes: These attributes are passed in the operation and affect the IPP object's behavior while processing the operation request and may affect other attributes or groups of attributes. Some operation attributes describe the document data associated with the print job and are associated with new Job objects, however most operation attributes do not persist beyond the life of the operation. The description of each operation attribute includes conformance statements indicating which operation attributes are REQUIRED and which are OPTIONAL
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for an IPP object to support and which attributes a client MUST supply in a request and an IPP object MUST supply in a response. - Job Template Attributes: These attributes affect the processing of a job. A client OPTIONALLY supplies Job Template Attributes in a create request, and the receiving object MUST be prepared to receive all supported attributes. The Job object can later be queried to find out what Job Template attributes were originally requested in the create request, and such attributes are returned in the response as Job Object Attributes. The Printer object can be queried about its Job Template attributes to find out what type of job processing capabilities are supported and/or what the default job processing behaviors are, though such attributes are returned in the response as Printer Object Attributes. The "ipp-attribute-fidelity" operation attribute affects processing of all client-supplied Job Template attributes (see sections 3.2.1.2 and 15 for a full description of "ipp-attribute-fidelity" and its relationship to other attributes). - Job Object Attributes: These attributes are returned in response to a query operation directed at a Job object. - Printer Object Attributes: These attributes are returned in response to a query operation directed at a Printer object. - Unsupported Attributes: In a create request, the client supplies a set of Operation and Job Template attributes. If any of these attributes or their values is unsupported by the Printer object, the Printer object returns the set of unsupported attributes in the response. Sections 3.1.7, 3.2.1.2, and 15 give a full description of how Job Template attributes supplied by the client in a create request are processed by the Printer object and how unsupported attributes are returned to the client. Because of extensibility, any IPP object might receive a request that contains new or unknown attributes or values for which it has no support. In such cases, the IPP object processes what it can and returns the unsupported attributes in the response. The Unsupported Attribute group is defined for all operation responses for returning unsupported attributes that the client supplied in the request.
Later in this section, each operation is formally defined by identifying the allowed and expected groups of attributes for each request and response. The model identifies a specific order for each group in each request or response, but the attributes within each group may be in any order, unless specified otherwise.
The attributes within a group MUST be unique; if an attribute with the same name occurs more than once, the group is mal-formed. Clients MUST NOT submit such malformed requests and Printers MUST NOT return such malformed responses. If such a malformed request is
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submitted to a Printer, the Printer MUST either (1) reject the request with the 'client-error-bad-request' status code (see section 13.1.4.1) or (2) process the request normally after selecting only one of the attribute instances, depending on implementation. Which attribute is selected when there are duplicate attributes depends on implementation. The IPP Printer MUST NOT use the values from more than one such duplicate attribute instance.
Each attribute definition includes the attribute's name followed by the name of its attribute syntax(es) in parenthesizes. In addition, each 'integer' attribute is followed by the allowed range in parentheses, (m:n), for values of that attribute. Each 'text' or 'name' attribute is followed by the maximum size in octets in parentheses, (size), for values of that attribute. For more details on attribute syntax notation, see the descriptions of these attributes syntaxes in section 4.1.
Note: Document data included in the operation is not strictly an attribute, but it is treated as a special attribute group for ordering purposes. The only operations that support supplying the document data within an operation request are Print-Job and Send- Document. There are no operation responses that include document data.
Some operations are REQUIRED for IPP objects to support; the others are OPTIONAL (see section 5.2.2). Therefore, before using an OPTIONAL operation, a client SHOULD first use the REQUIRED Get- Printer-Attributes operation to query the Printer's "operations- supported" attribute in order to determine which OPTIONAL Printer and Job operations are actually supported. The client SHOULD NOT use an OPTIONAL operation that is not supported. When an IPP object receives a request to perform an operation it does not support, it returns the 'server-error-operation-not-supported' status code (see section 13.1.5.2). An IPP object is non-conformant if it does not support a REQUIRED operation.
3.1.4 Character Set and Natural Language Operation Attributes
Some Job and Printer attributes have values that are text strings and names intended for human understanding rather than machine understanding (see the 'text' and 'name' attribute syntax descriptions in section 4.1). The following sections describe two special Operation Attributes called "attributes-charset" and "attributes-natural-language". These attributes are always part of the Operation Attributes group. For most attribute groups, the order of the attributes within the group is not important. However, for these two attributes within the Operation Attributes group, the order is critical. The "attributes-charset" attribute MUST be the first
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attribute in the group and the "attributes-natural-language" attribute MUST be the second attribute in the group. In other words, these attributes MUST be supplied in every IPP request and response, they MUST come first in the group, and MUST come in the specified order. For job creation operations, the IPP Printer implementation saves these two attributes with the new Job object as Job Description attributes. For the sake of brevity in this document, these operation attribute descriptions are not repeated with every operation request and response, but have a reference back to this section instead.
The client MUST supply and the Printer object MUST support the following REQUIRED operation attributes in every IPP/1.1 operation request:
"attributes-charset" (charset): This operation attribute identifies the charset (coded character set and encoding method) used by any 'text' and 'name' attributes that the client is supplying in this request. It also identifies the charset that the Printer object MUST use (if supported) for all 'text' and 'name' attributes and status messages that the Printer object returns in the response to this request. See Sections 4.1.1 and 4.1.2 for the definition of the 'text' and 'name' attribute syntaxes.
All clients and IPP objects MUST support the 'utf-8' charset [RFC2279] and MAY support additional charsets provided that they are registered with IANA [IANA-CS]. If the Printer object does not support the client supplied charset value, the Printer object MUST reject the request, set the "attributes-charset" to 'utf-8' in the response, and return the 'client-error-charset- not-supported' status code and any 'text' or 'name' attributes using the 'utf-8' charset. The Printer NEED NOT return any attributes in the Unsupported Attributes Group (See sections 3.1.7 and 3.2.1.2). The Printer object MUST indicate the charset(s) supported as the values of the "charset-supported" Printer attribute (see Section 4.4.18), so that the client can query to determine which charset(s) are supported.
Note to client implementers: Since IPP objects are only required to support the 'utf-8' charset, in order to maximize interoperability with multiple IPP object implementations, a client may want to supply 'utf-8' in the "attributes-charset" operation attribute, even though the client is only passing and able to present a simpler charset, such as US-ASCII [ASCII] or ISO-8859-1 [ISO8859-1]. Then the client will have to filter
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out (or charset convert) those characters that are returned in the response that it cannot present to its user. On the other hand, if both the client and the IPP objects also support a charset in common besides utf-8, the client may want to use that charset in order to avoid charset conversion or data loss.
See the 'charset' attribute syntax description in Section 4.1.7 for the syntax and semantic interpretation of the values of this attribute and for example values.
"attributes-natural-language" (naturalLanguage): This operation attribute identifies the natural language used by any 'text' and 'name' attributes that the client is supplying in this request. This attribute also identifies the natural language that the Printer object SHOULD use for all 'text' and 'name' attributes and status messages that the Printer object returns in the response to this request. See the 'naturalLanguage' attribute syntax description in section 4.1.8 for the syntax and semantic interpretation of the values of this attribute and for example values.
There are no REQUIRED natural languages required for the Printer object to support. However, the Printer object's "generated-natural-language-supported" attribute identifies the natural languages supported by the Printer object and any contained Job objects for all text strings generated by the IPP object. A client MAY query this attribute to determine which natural language(s) are supported for generated messages.
For any of the attributes for which the Printer object generates text, i.e., for the "job-state-message", "printer- state-message", and status messages (see Section 3.1.6), the Printer object MUST be able to generate these text strings in any of its supported natural languages. If the client requests a natural language that is not supported, the Printer object MUST return these generated messages in the Printer's configured natural language as specified by the Printer's "natural-language-configured" attribute" (see Section 4.4.19).
For other 'text' and 'name' attributes supplied by the client, authentication system, operator, system administrator, or manufacturer (i.e., for "job-originating-user-name", "printer- name" (name), "printer-location" (text), "printer-info" (text), and "printer-make-and-model" (text)), the Printer object is only required to support the configured natural language of the
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Printer identified by the Printer object's "natural-language- configured" attribute, though support of additional natural languages for these attributes is permitted.
For any 'text' or 'name' attribute in the request that is in a different natural language than the value supplied in the "attributes-natural-language" operation attribute, the client MUST use the Natural Language Override mechanism (see sections 4.1.1.2 and 4.1.2.2) for each such attribute value supplied. The client MAY use the Natural Language Override mechanism redundantly, i.e., use it even when the value is in the same natural language as the value supplied in the "attributes- natural-language" operation attribute of the request.
The IPP object MUST accept any natural language and any Natural Language Override, whether the IPP object supports that natural language or not (and independent of the value of the "ipp- attribute-fidelity" Operation attribute). That is the IPP object accepts all client supplied values no matter what the values are in the Printer object's "generated-natural- language-supported" attribute. That attribute, "generated- natural-language-supported", only applies to generated messages, not client supplied messages. The IPP object MUST remember that natural language for all client-supplied attributes, and when returning those attributes in response to a query, the IPP object MUST indicate that natural language.
Each value whose attribute syntax type is 'text' or 'name' (see sections 4.1.1 and 4.1.2) has an Associated Natural-Language. This document does not specify how this association is stored in a Printer or Job object. When such a value is encoded in a request or response, the natural language is either implicit or explicit:
- In the implicit case, the value contains only the text/name value, and the language is specified by the "attributes- natural-language" operation attribute in the request or response (see sections 4.1.1.1 textWithoutLanguage and 4.1.2.1 nameWithoutLanguage).
- In the explicit case (also known as the Natural-Language Override case), the value contains both the language and the text/name value (see sections 4.1.1.2 textWithLanguage and 4.1.2.2 nameWithLanguage).
For example, the "job-name" attribute MAY be supplied by the client in a create request. The text value for this attribute will be in the natural language identified by the "attribute-
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natural-language" attribute, or if different, as identified by the Natural Language Override mechanism. If supplied, the IPP object will use the value of the "job-name" attribute to populate the Job object's "job-name" attribute. Whenever any client queries the Job object's "job-name" attribute, the IPP object returns the attribute as stored and uses the Natural Language Override mechanism to specify the natural language, if it is different from that reported in the "attributes-natural- language" operation attribute of the response. The IPP object MAY use the Natural Language Override mechanism redundantly, i.e., use it even when the value is in the same natural language as the value supplied in the "attributes-natural- language" operation attribute of the response.
An IPP object MUST NOT reject a request based on a supplied natural language in an "attributes-natural-language" Operation attribute or in any attribute that uses the Natural Language Override.
Clients SHOULD NOT supply 'text' or 'name' attributes that use an illegal combination of natural language and charset. For example, suppose a Printer object supports charsets 'utf-8', 'iso-8859-1', and 'iso-8859-7'. Suppose also, that it supports natural languages 'en' (English), 'fr' (French), and 'el' (Greek). Although the Printer object supports the charset 'iso-8859-1' and natural language 'el', it probably does not support the combination of Greek text strings using the 'iso-8859-1' charset. The Printer object handles this apparent incompatibility differently depending on the context in which it occurs:
- In a create request: If the client supplies a text or name attribute (for example, the "job-name" operation attribute) that uses an apparently incompatible combination, it is a client choice that does not affect the Printer object or its correct operation. Therefore, the Printer object simply accepts the client supplied value, stores it with the Job object, and responds back with the same combination whenever the client (or any client) queries for that attribute. - In a query-type operation, like Get-Printer-Attributes: If the client requests an apparently incompatible combination, the Printer object responds (as described in section 3.1.4.2) using the Printer's configured natural language rather than the natural language requested by the client.
In either case, the Printer object does not reject the request because of the apparent incompatibility. The potential incompatible combination of charset and natural language can occur either at the global operation level or at the Natural Language Override
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attribute-by-attribute level. In addition, since the response always includes explicit charset and natural language information, there is never any question or ambiguity in how the client interprets the response.
The Printer object MUST supply and the client MUST support the following REQUIRED operation attributes in every IPP/1.1 operation response:
"attributes-charset" (charset): This operation attribute identifies the charset used by any 'text' and 'name' attributes that the Printer object is returning in this response. The value in this response MUST be the same value as the "attributes-charset" operation attribute supplied by the client in the request. If this is not possible (i.e., the charset requested is not supported), the request would have been rejected. See "attributes-charset" described in Section 3.1.4.1 above.
If the Printer object supports more than just the 'utf-8' charset, the Printer object MUST be able to code convert between each of the charsets supported on a highest fidelity possible basis in order to return the 'text' and 'name' attributes in the charset requested by the client. However, some information loss MAY occur during the charset conversion depending on the charsets involved. For example, the Printer object may convert from a UTF-8 'a' to a US-ASCII 'a' (with no loss of information), from an ISO Latin 1 CAPITAL LETTER A WITH ACUTE ACCENT to US-ASCII 'A' (losing the accent), or from a UTF-8 Japanese Kanji character to some ISO Latin 1 error character indication such as '?', decimal code equivalent, or to the absence of a character, depending on implementation.
Whether an implementation that supports more than one charset stores the data in the charset supplied by the client or code converts to one of the other supported charsets, depends on implementation. The strategy should try to minimize loss of information during code conversion. On each response, such an implementation converts from its internal charset to that requested.
"attributes-natural-language" (naturalLanguage): This operation attribute identifies the natural language used by any 'text' and 'name' attributes that the IPP object is returning in this response. Unlike the "attributes-charset" operation attribute, the IPP object NEED NOT return the same
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value as that supplied by the client in the request. The IPP object MAY return the natural language of the Job object or the Printer's configured natural language as identified by the Printer object's "natural-language-configured" attribute, rather than the natural language supplied by the client. For any 'text' or 'name' attribute or status message in the response that is in a different natural language than the value returned in the "attributes-natural-language" operation attribute, the IPP object MUST use the Natural Language Override mechanism (see sections 4.1.1.2 and 4.1.2.2) on each attribute value returned. The IPP object MAY use the Natural Language Override mechanism redundantly, i.e., use it even when the value is in the same natural language as the value supplied in the "attributes-natural-language" operation attribute of the response.
All IPP operations are directed at IPP objects. For Printer operations, the operation is always directed at a Printer object using one of its URIs (i.e., one of the values in the Printer object's "printer-uri-supported" attribute). Even if the Printer object supports more than one URI, the client supplies only one URI as the target of the operation. The client identifies the target object by supplying the correct URI in the "printer-uri (uri)" operation attribute.
For Job operations, the operation is directed at either:
- The Job object itself using the Job object's URI. In this case, the client identifies the target object by supplying the correct URI in the "job-uri (uri)" operation attribute. - The Printer object that created the Job object using both the Printer objects URI and the Job object's Job ID. Since the Printer object that created the Job object generated the Job ID, it MUST be able to correctly associate the client supplied Job ID with the correct Job object. The client supplies the Printer object's URI in the "printer-uri (uri)" operation attribute and the Job object's Job ID in the "job-id (integer(1:MAX))" operation attribute.
If the operation is directed at the Job object directly using the Job object's URI, the client MUST NOT include the redundant "job-id" operation attribute.
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The operation target attributes are REQUIRED operation attributes that MUST be included in every operation request. Like the charset and natural language attributes (see section 3.1.4), the operation target attributes are specially ordered operation attributes. In all cases, the operation target attributes immediately follow the "attributes-charset" and "attributes-natural-language" attributes within the operation attribute group, however the specific ordering rules are:
- In the case where there is only one operation target attribute (i.e., either only the "printer-uri" attribute or only the "job-uri" attribute), that attribute MUST be the third attribute in the operation attributes group. - In the case where Job operations use two operation target attributes (i.e., the "printer-uri" and "job-id" attributes), the "printer-uri" attribute MUST be the third attribute and the "job-id" attribute MUST be the fourth attribute.
In all cases, the target URIs contained within the body of IPP operation requests and responses must be in absolute format rather than relative format (a relative URL identifies a resource with the scope of the HTTP server, but does not include scheme, host or port).
The following rules apply to the use of port numbers in URIs that identify IPP objects:
1. If the URI scheme allows the port number to be explicitly included in the URI string, and a port number is specified within the URI, then that port number MUST be used by the client to contact the IPP object.
2. If the URI scheme allows the port number to be explicitly included in the URI string, and a port number is not specified within the URI, then default port number implied by that URI scheme MUST be used by the client to contact the IPP object.
3. If the URI scheme does not allow an explicit port number to be specified within the URI, then the default port number implied by that URI MUST be used by the client to contact the IPP object.
Note: The IPP "Encoding and Transport document [RFC2910] shows a mapping of IPP onto HTTP/1.1 [RFC2616] and defines a new default port number for using IPP over HTTP/1.1.
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3.1.6 Operation Response Status Codes and Status Messages
Every operation response includes a REQUIRED "status-code" parameter and an OPTIONAL "status-message" operation attribute, and an OPTIONAL "detailed-status-message" operation attribute. The Print-URI and Send-URI response MAY include an OPTIONAL "document-access-error" operation attribute.
The REQUIRED "status-code" parameter provides information on the processing of a request.
The status code is intended for use by automata. A client implementation of IPP SHOULD convert status code values into any localized message that has semantic meaning to the end user.
The "status-code" value is a numeric value that has semantic meaning. The "status-code" syntax is similar to a "type2 enum" (see section 4.1 on "Attribute Syntaxes") except that values can range only from 0x0000 to 0x7FFF. Section 13 describes the status codes, assigns the numeric values, and suggests a corresponding status message for each status code for use by the client when the user's natural language is English.
If the Printer performs an operation with no errors and it encounters no problems, it MUST return the status code 'successful-ok' in the response. See section 13.
If the client supplies unsupported values for the following parameters or Operation attributes, the Printer object MUST reject the operation, NEED NOT return the unsupported attribute value in the Unsupported Attributes group, and MUST return the indicated status code:
If the client supplies unsupported values for other attributes, or unsupported attributes, the Printer returns the status code defined in section 3.1.7 on Unsupported Attributes.
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The OPTIONAL "status-message" operation attribute provides a short textual description of the status of the operation. The "status- message" attribute's syntax is "text(255)", so the maximum length is 255 octets (see section 4.1.1). The status message is intended for the human end user. If a response does include a "status-message" attribute, an IPP client NEED NOT examine or display the messages, however it SHOULD do so in some implementation specific manner. The "status-message" is especially useful for a later version of a Printer object to return as supplemental information for the human user to accompany a status code that an earlier version of a client might not understand.
If the Printer object supports the "status-message" operation attribute, the Printer object MUST be able to generate this message in any of the natural languages identified by the Printer object's "generated-natural-language-supported" attribute (see the "attributes-natural-language" operation attribute specified in section 3.1.4.1. Section 13 suggests the text for the status message returned by the Printer for use with the English natural language.
As described in section 3.1.4.1 for any returned 'text' attribute, if there is a choice for generating this message, the Printer object uses the natural language indicated by the value of the "attributes- natural-language" in the client request if supported, otherwise the Printer object uses the value in the Printer object's own "natural- language-configured" attribute.
If the Printer object supports the "status-message" operation attribute, it SHOULD use the REQUIRED 'utf-8' charset to return a status message for the following error status codes (see section 13): 'client-error-bad-request', 'client-error-charset-not-supported', 'server-error-internal-error', 'server-error-operation-not- supported', and 'server-error-version-not-supported'. In this case, it MUST set the value of the "attributes-charset" operation attribute to 'utf-8' in the error response.
The OPTIONAL "detailed-status-message" operation attribute provides additional more detailed technical and implementation-specific information about the operation. The "detailed-status-message" attribute's syntax is "text(MAX)", so the maximum length is 1023 octets (see section 4.1.1). If the Printer objects supports the "detailed-status-message" operation attribute, the Printer NEED NOT localize the message, since it is intended for use by the system administrator or other experienced technical persons. Localization
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might obscure the technical meaning of such messages. Clients MUST NOT attempt to parse the value of this attribute. See the "document-access-error" operation attribute (section 3.1.6.4) for additional errors that a program can process.
This OPTIONAL operation attribute provides additional information about any document access errors encountered by the Printer before it returned a response to the Print-URI (section 3.2.2) or Send-URI (section 3.3.1) operation. For errors in the protocol identified by the URI scheme in the "document-uri" operation attribute, such as 'http:' or 'ftp:', the error code is returned in parentheses, followed by the URI. For example:
The Unsupported Attributes group contains attributes that are not supported by the operation. This group is primarily for the job creation operations, but all operations can return this group.
A Printer object MUST include an Unsupported Attributes group in a response if the status code is one of the following: 'successful- ok-ignored-or-substituted-attributes', 'successful-ok-conflicting- attributes', 'client-error-attributes-or-values-not-supported' or 'client-error-conflicting-attributes'.
If the status code is one of the four specified in the preceding paragraph, the Unsupported Attributes group MUST contain all of those attributes and only those attributes that are:
a. an Operation or Job Template attribute supplied in the request, and
b. unsupported by the printer. See below for details on the three categories "unsupported" attributes.
If the status code is one of those in the table in section 3.1.6.1, the Unsupported Attributes group NEED NOT contain the unsupported parameter or attribute indicated in that table.
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If the Printer object is not returning any Unsupported Attributes in the response, the Printer object SHOULD omit Group 2 rather than sending an empty group. However, a client MUST be able to accept an empty group.
Unsupported attributes fall into three categories:
1. The Printer object does not support the supplied attribute (no matter what the attribute syntax or value).
2. The Printer object does support the attribute, but does not support some or all of the particular attribute syntaxes or values supplied by the client (i.e., the Printer object does not have those attribute syntaxes or values in its corresponding "xxx-supported" attribute).
3. The Printer object does support the attributes and values supplied, but the particular values are in conflict with one another, because they violate a constraint, such as not being able to staple transparencies.
In the case of an unsupported attribute name, the Printer object returns the client-supplied attribute with a substituted value of 'unsupported'. This value's syntax type is "out-of-band" and its encoding is defined by special rules for "out-of-band" values in the "Encoding and Transport" document [RFC2910]. Its value indicates no support for the attribute itself (see the beginning of section 4.1).
In the case of a supported attribute with one or more unsupported attribute syntaxes or values, the Printer object simply returns the client-supplied attribute with the unsupported attribute syntaxes or values as supplied by the client. This indicates support for the attribute, but no support for that particular attribute syntax or value. If the client supplies a multi-valued attribute with more than one value and the Printer object supports the attribute but only supports a subset of the client-supplied attribute syntaxes or values, the Printer object
MUST return only those attribute syntaxes or values that are unsupported.
In the case of two (or more) supported attribute values that are in conflict with one another (although each is supported independently, the values conflict when requested together within the same job), the Printer object MUST return all the values that it ignores or substitutes to resolve the conflict, but not any of the values that
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it is still using. The choice for exactly how to resolve the conflict is implementation dependent. See sections 3.2.1.2 and 15. See The Implementer's Guide [IPP-IIG] for an example.
Each operation request and response carries with it a "version- number" parameter. Each value of the "version-number" is in the form "X.Y" where X is the major version number and Y is the minor version number. By including a version number in the client request, it allows the client to identify which version of IPP it is interested in using, i.e., the version whose conformance requirements the client may be depending upon the Printer to meet.
If the IPP object does not support that major version number supplied by the client, i.e., the major version field of the "version-number" parameter does not match any of the values of the Printer's "ipp- versions-supported" (see section 4.4.14), the object MUST respond with a status code of 'server-error-version-not-supported' along with the closest version number that is supported (see section 13.1.5.4). If the major version number is supported, but the minor version number is not, the IPP object SHOULD accept and attempt to perform the request (or reject the request if the operation is not supported), else it rejects the request and returns the 'server- error-version-not-supported' status code. In all cases, the IPP object MUST return the "version-number" that it supports that is closest to the version number supplied by the client in the request.
There is no version negotiation per se. However, if after receiving a 'server-error-version-not-supported' status code from an IPP object, a client SHOULD try again with a different version number. A client MAY also determine the versions supported either from a directory that conforms to Appendix E (see section 16) or by querying the Printer object's "ipp-versions-supported" attribute (see section 4.4.14) to determine which versions are supported.
An IPP object implementation MUST support version '1.1', i.e., meet the conformance requirements for IPP/1.1 as specified in this document and [RFC2910]. It is recommended that IPP object implementations accept any request with the major version '1' (or reject the request if the operation is not supported).
There is only one notion of "version number" that covers both IPP Model and IPP Protocol changes. Thus the version number MUST change when introducing a new version of the Model and Semantics document (this document) or a new version of the "Encoding and Transport" document [RFC2910].
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Changes to the major version number of the Model and Semantics document indicate structural or syntactic changes that make it impossible for older version of IPP clients and Printer objects to correctly parse and correctly process the new or changed attributes, operations and responses. If the major version number changes, the minor version numbers is set to zero. As an example, adding the REQUIRED "ipp-attribute-fidelity" attribute to version '1.1' (if it had not been part of version '1.0'), would have required a change to the major version number, since an IPP/1.0 Printer would not have processed a request with the correct semantics that contained the "ipp-attribute-fidelity" attribute that it did not know about. Items that might affect the changing of the major version number include any changes to the Model and Semantics document (this document) or the "Encoding and Transport" document [RFC2910] itself, such as:
- reordering of ordered attributes or attribute sets - changes to the syntax of existing attributes - adding REQUIRED (for an IPP object to support) operation attribute groups - adding values to existing REQUIRED operation attributes - adding REQUIRED operations
Changes to the minor version number indicate the addition of new features, attributes and attribute values that may not be understood by all IPP objects, but which can be ignored if not understood. Items that might affect the changing of the minor version number include any changes to the model objects and attributes but not the encoding and transport rules [RFC2910] (except adding attribute syntaxes). Examples of such changes are:
- grouping all extensions not included in a previous version into a new version - adding new attribute values - adding new object attributes - adding OPTIONAL (for an IPP object to support) operation attributes (i.e., those attributes that an IPP object can ignore without confusing clients) - adding OPTIONAL (for an IPP object to support) operation attribute groups (i.e., those attributes that an IPP object can ignore without confusing clients) - adding new attribute syntaxes - adding OPTIONAL operations - changing Job Description attributes or Printer Description attributes from OPTIONAL to REQUIRED or vice versa. - adding OPTIONAL attribute syntaxes to an existing attribute.
The encoding of the "version-number" MUST NOT change over any version number (either major or minor). This rule guarantees that all future
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versions will be backwards compatible with all previous versions (at least for checking the "version-number"). In addition, any protocol elements (attributes, error codes, tags, etc.) that are not carried forward from one version to the next are deprecated so that they can never be reused with new semantics.
Implementations that support a certain version NEED NOT support ALL previous versions. As each new version is defined (through the release of a new IPP specification document), that version will specify which previous versions MUST and which versions SHOULD be supported in compliant implementations.
In order to "submit a print job" and create a new Job object, a client issues a create request. A create request is any one of following three operation requests:
- The Print-Job Request: A client that wants to submit a print job with only a single document uses the Print-Job operation. The operation allows for the client to "push" the document data to the Printer object by including the document data in the request itself.
- The Print-URI Request: A client that wants to submit a print job with only a single document (where the Printer object "pulls" the document data instead of the client "pushing" the data to the Printer object) uses the Print-URI operation. In this case, the client includes in the request only a URI reference to the document data (not the document data itself).
- The Create-Job Request: A client that wants to submit a print job with multiple documents uses the Create-Job operation. This operation is followed by an arbitrary number (one or more) of Send-Document and/or Send-URI operations (each creating another document for the newly create Job object). The Send-Document operation includes the document data in the request (the client "pushes" the document data to the printer), and the Send-URI operation includes only a URI reference to the document data in the request (the Printer "pulls" the document data from the referenced location). The last Send-Document or Send-URI request for a given Job object includes a "last-document" operation attribute set to 'true' indicating that this is the last request.
Throughout this model document, the term "create request" is used to refer to any of these three operation requests.
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A Create-Job operation followed by only one Send-Document operation is semantically equivalent to a Print-Job operation, however, for performance reasons, the client SHOULD use the Print-Job operation for all single document jobs. Also, Print-Job is a REQUIRED operation (all implementations MUST support it) whereas Create-Job is an OPTIONAL operation, hence some implementations might not support it.
Job submission time is the point in time when a client issues a create request. The initial state of every Job object is the 'pending', 'pending-held', or 'processing' state (see section 4.3.7). When the Printer object begins processing the print job, the Job object's state moves to 'processing'. This is known as job processing time. There are validation checks that must be done at job submission time and others that must be performed at job processing time.
At job submission time and at the time a Validate-Job operation is received, the Printer MUST do the following:
1. Process the client supplied attributes and either accept or reject the request 2. Validate the syntax of and support for the scheme of any client supplied URI
At job submission time the Printer object MUST validate whether or not the supplied attributes, attribute syntaxes, and values are supported by matching them with the Printer object's corresponding "xxx-supported" attributes. See section 3.1.7 for details. [IPP- IIG] presents suggested steps for an IPP object to either accept or reject any request and additional steps for processing create requests.
At job submission time the Printer object NEED NOT perform the validation checks reserved for job processing time such as:
1. Validating the document data 2. Validating the actual contents of any client supplied URI (resolve the reference and follow the link to the document data)
At job submission time, these additional job processing time validation checks are essentially useless, since they require actually parsing and interpreting the document data, are not guaranteed to be 100% accurate, and MUST be done, yet again, at job processing time. Also, in the case of a URI, checking for availability at job submission time does not guarantee availability
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at job processing time. In addition, at job processing time, the Printer object might discover any of the following conditions that were not detectable at job submission time:
- runtime errors in the document data, - nested document data that is in an unsupported format, - the URI reference is no longer valid (i.e., the server hosting the document might be down), or - any other job processing error
At job submission time, a Printer object, especially a non-spooling Printer, MAY accept jobs that it does not have enough space for. In such a situation, a Printer object MAY stop reading data from a client for an indefinite period of time. A client MUST be prepared for a write operation to block for an indefinite period of time (see section 5.1 on client conformance).
When a Printer object has too little space for starting a new job, it MAY reject a new create request. In this case, a Printer object MUST return a response (in reply to the rejected request) with a status- code of 'server-error-busy' (see section 14.1.5.8) and it MAY close the connection before receiving all bytes of the operation. A Printer SHOULD indicate that it is temporarily unable to accept jobs by setting the 'spool-space-full' value in its "printer-state- reasons" attribute and removing the value when it can accept another job (see section 4.4.12).
When receiving a 'server-error-busy' status-code in an operation response, a client MUST be prepared for the Printer object to close the connection before the client has sent all of the data (especially for the Print-Job operation). A client MUST be prepared to keep submitting a create request until the IPP Printer object accepts the create request.
At job processing time, since the Printer object has already responded with a successful status code in the response to the create request, if the Printer object detects an error, the Printer object is unable to inform the end user of the error with an operation status code. In this case, the Printer, depending on the error, can set the job object's "job-state", "job-state-reasons", or "job- state-message" attributes to the appropriate value(s) so that later queries can report the correct job status.
Note: Asynchronous notification of events is outside the scope of this IPP/1.1 document.
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All Printer operations are directed at Printer objects. A client MUST always supply the "printer-uri" operation attribute in order to identify the correct target of the operation.
This REQUIRED operation allows a client to submit a print job with only one document and supply the document data (rather than just a reference to the data). See Section 15 for the suggested steps for processing create operations and their Operation and Job Template attributes.
The following groups of attributes are supplied as part of the Print-Job Request:
Group 1: Operation Attributes
Natural Language and Character Set: The "attributes-charset" and "attributes-natural-language" attributes as described in section 3.1.4.1. The Printer object MUST copy these values to the corresponding Job Description attributes described in sections 4.3.19 and 4.3.20.
Target: The "printer-uri" (uri) operation attribute which is the target for this operation as described in section 3.1.5.
Requesting User Name: The "requesting-user-name" (name(MAX)) attribute SHOULD be supplied by the client as described in section 8.3.
"job-name" (name(MAX)): The client OPTIONALLY supplies this attribute. The Printer object MUST support this attribute. It contains the client supplied Job name. If this attribute is supplied by the client, its value is used for the "job-name" attribute of the newly created Job object. The client MAY automatically include any information that will help the end-user distinguish amongst his/her jobs, such as the name of the application program along with information from the document, such as the document name, document subject, or source file name. If this attribute is not supplied by the client, the Printer generates a name to use in the "job-name" attribute of the newly created Job object (see Section 4.3.5).
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"ipp-attribute-fidelity" (boolean): The client OPTIONALLY supplies this attribute. The Printer object MUST support this attribute. The value 'true' indicates that total fidelity to client supplied Job Template attributes and values is required, else the Printer object MUST reject the Print-Job request. The value 'false' indicates that a reasonable attempt to print the Job object is acceptable and the Printer object MUST accept the Print-Job request. If not supplied, the Printer object assumes the value is 'false'. All Printer objects MUST support both types of job processing. See section 15 for a full description of "ipp-attribute-fidelity" and its relationship to other attributes, especially the Printer object's "pdl-override-supported" attribute.
"document-name" (name(MAX)): The client OPTIONALLY supplies this attribute. The Printer object MUST support this attribute. It contains the client supplied document name. The document name MAY be different than the Job name. Typically, the client software automatically supplies the document name on behalf of the end user by using a file name or an application generated name. If this attribute is supplied, its value can be used in a manner defined by each implementation. Examples include: printed along with the Job (job start sheet, page adornments, etc.), used by accounting or resource tracking management tools, or even stored along with the document as a document level attribute. IPP/1.1 does not support the concept of document level attributes.
"compression" (type3 keyword): The client OPTIONALLY supplies this attribute. The Printer object MUST support this attribute and the "compression- supported" attribute (see section 4.4.32). The client supplied "compression" operation attribute identifies the compression algorithm used on the document data. The following cases exist:
a) If the client omits this attribute, the Printer object MUST assume that the data is not compressed (i.e. the Printer follows the rules below as if the client supplied the "compression" attribute with a value of 'none'). b) If the client supplies this attribute, but the value is not supported by the Printer object, i.e., the value is not one of the values of the Printer object's "compression- supported" attribute, the Printer object MUST reject the request, and return the 'client-error-compression-not- supported' status code. See section 3.1.7 for returning unsupported attributes and values.
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c) If the client supplies the attribute and the Printer object supports the attribute value, the Printer object uses the corresponding decompression algorithm on the document data. d) If the decompression algorithm fails before the Printer returns an operation response, the Printer object MUST reject the request and return the 'client-error- compression-error' status code. e) If the decompression algorithm fails after the Printer returns an operation response, the Printer object MUST abort the job and add the 'compression-error' value to the job's "job-state-reasons" attribute. f) If the decompression algorithm succeeds, the document data MUST then have the format specified by the job's "document- format" attribute, if supplied (see "document-format" operation attribute definition below).
"document-format" (mimeMediaType): The client OPTIONALLY supplies this attribute. The Printer object MUST support this attribute. The value of this attribute identifies the format of the supplied document data. The following cases exist:
a) If the client does not supply this attribute, the Printer object assumes that the document data is in the format defined by the Printer object's "document-format-default" attribute. (i.e. the Printer follows the rules below as if the client supplied the "document-format" attribute with a value equal to the printer's default value). b) If the client supplies this attribute, but the value is not supported by the Printer object, i.e., the value is not one of the values of the Printer object's "document-format- supported" attribute, the Printer object MUST reject the request and return the 'client-error-document-format-not- supported' status code. c) If the client supplies this attribute and its value is 'application/octet-stream' (i.e. to be auto-sensed, see Section 4.1.9.1), and the format is not one of the document-formats that the Printer can auto-sense, and this check occurs before the Printer returns an operation response, then the Printer MUST reject the request and return the 'client-error-document-format-not-supported' status code. d) If the client supplies this attribute, and the value is supported by the Printer object, the Printer is capable of interpreting the document data.
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e) If interpreting of the document data fails before the Printer returns an operation response, the Printer object MUST reject the request and return the 'client-error- document-format-error' status code. f) If interpreting of the document data fails after the Printer returns an operation response, the Printer object MUST abort the job and add the 'document-format-error' value to the job's "job-state-reasons" attribute.
"document-natural-language" (naturalLanguage): The client OPTIONALLY supplies this attribute. The Printer object OPTIONALLY supports this attribute. This attribute specifies the natural language of the document for those document-formats that require a specification of the natural language in order to image the document unambiguously. There are no particular values required for the Printer object to support.
"job-k-octets" (integer(0:MAX)): The client OPTIONALLY supplies this attribute. The Printer object OPTIONALLY supports this attribute and the "job-k- octets-supported" attribute (see section 4.4.33). The client supplied "job-k-octets" operation attribute identifies the total size of the document(s) in K octets being submitted (see section 4.3.17.1 for the complete semantics). If the client supplies the attribute and the Printer object supports the attribute, the value of the attribute is used to populate the Job object's "job-k-octets" Job Description attribute.
For this attribute and the following two attributes ("job- impressions", and "job-media-sheets"), if the client supplies the attribute, but the Printer object does not support the attribute, the Printer object ignores the client-supplied value. If the client supplies the attribute and the Printer supports the attribute, and the value is within the range of the corresponding Printer object's "xxx-supported" attribute, the Printer object MUST use the value to populate the Job object's "xxx" attribute. If the client supplies the attribute and the Printer supports the attribute, but the value is outside the range of the corresponding Printer object's "xxx- supported" attribute, the Printer object MUST copy the attribute and its value to the Unsupported Attributes response group, reject the request, and return the 'client-error- attributes-or-values-not-supported' status code. If the client does not supply the attribute, the Printer object MAY choose to populate the corresponding Job object attribute depending on whether the Printer object supports the attribute and is able to calculate or discern the correct value.
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"job-impressions" (integer(0:MAX)): The client OPTIONALLY supplies this attribute. The Printer object OPTIONALLY supports this attribute and the "job- impressions-supported" attribute (see section 4.4.34). The client supplied "job-impressions" operation attribute identifies the total size in number of impressions of the document(s) being submitted (see section 4.3.17.2 for the complete semantics).
See last paragraph under "job-k-octets".
"job-media-sheets" (integer(0:MAX)): The client OPTIONALLY supplies this attribute. The Printer object OPTIONALLY supports this attribute and the "job-media- sheets-supported" attribute (see section 4.4.35). The client supplied "job-media-sheets" operation attribute identifies the total number of media sheets to be produced for this job (see section 4.3.17.3 for the complete semantics).
See last paragraph under "job-k-octets".
Group 2: Job Template Attributes
The client OPTIONALLY supplies a set of Job Template attributes as defined in section 4.2. If the client is not supplying any Job Template attributes in the request, the client SHOULD omit Group 2 rather than sending an empty group. However, a Printer object MUST be able to accept an empty group.
Group 3: Document Content
The client MUST supply the document data to be processed.
In addition to the MANDATORY parameters required for every operation request, the simplest Print-Job Request consists of just the "attributes-charset" and "attributes-natural-language" operation attributes; the "printer-uri" target operation attribute; the Document Content and nothing else. In this simple case, the Printer object:
- creates a new Job object (the Job object contains a single document), - stores a generated Job name in the "job-name" attribute in the natural language and charset requested (see Section 3.1.4.1) (if those are supported, otherwise using the Printer object's default natural language and charset), and
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- at job processing time, uses its corresponding default value attributes for the supported Job Template attributes that were not supplied by the client as IPP attribute or embedded instructions in the document data.
The Printer object MUST return to the client the following sets of attributes as part of the Print-Job Response:
Group 1: Operation Attributes
Status Message: In addition to the REQUIRED status code returned in every response, the response OPTIONALLY includes a "status-message" (text(255)) and/or a "detailed-status-message" (text(MAX)) operation attribute as described in sections 13 and 3.1.6. If the client supplies unsupported or conflicting Job Template attributes or values, the Printer object MUST reject or accept the Print-Job request depending on the whether the client supplied a 'true' or 'false' value for the "ipp-attribute- fidelity" operation attribute. See the Implementer's Guide [IPP-IIG] for a complete description of the suggested steps for processing a create request.
Natural Language and Character Set: The "attributes-charset" and "attributes-natural-language" attributes as described in section 3.1.4.2.
Group 2: Unsupported Attributes
See section 3.1.7 for details on returning Unsupported Attributes.
The value of the "ipp-attribute-fidelity" supplied by the client does not affect what attributes the Printer object returns in this group. The value of "ipp-attribute-fidelity" only affects whether the Print-Job operation is accepted or rejected. If the job is accepted, the client may query the job using the Get-Job- Attributes operation requesting the unsupported attributes that were returned in the create response to see which attributes were ignored (not stored on the Job object) and which attributes were stored with other (substituted) values.
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Group 3: Job Object Attributes
"job-uri" (uri): The Printer object MUST return the Job object's URI by returning the contents of the REQUIRED "job-uri" Job object attribute. The client uses the Job object's URI when directing operations at the Job object. The Printer object always uses its configured security policy when creating the new URI. However, if the Printer object supports more than one URI, the Printer object also uses information about which URI was used in the Print-Job Request to generated the new URI so that the new URI references the correct access channel. In other words, if the Print-Job Request comes in over a secure channel, the Printer object MUST generate a Job URI that uses the secure channel as well.
"job-id" (integer(1:MAX)): The Printer object MUST return the Job object's Job ID by returning the REQUIRED "job-id" Job object attribute. The client uses this "job-id" attribute in conjunction with the "printer-uri" attribute used in the Print-Job Request when directing Job operations at the Printer object.
"job-state" (type1 enum): The Printer object MUST return the Job object's REQUIRED "job- state" attribute. The value of this attribute (along with the value of the next attribute: "job-state-reasons") is taken from a "snapshot" of the new Job object at some meaningful point in time (implementation defined) between when the Printer object receives the Print-Job Request and when the Printer object returns the response.
"job-state-reasons" (1setOf type2 keyword): The Printer object MUST return the Job object's REQUIRED "job- state-reasons" attribute.
"job-state-message" (text(MAX)): The Printer object OPTIONALLY returns the Job object's OPTIONAL "job-state-message" attribute. If the Printer object supports this attribute then it MUST be returned in the response. If this attribute is not returned in the response, the client can assume that the "job-state-message" attribute is not supported and will not be returned in a subsequent Job object query.
"number-of-intervening-jobs" (integer(0:MAX)): The Printer object OPTIONALLY returns the Job object's OPTIONAL "number-of-intervening-jobs" attribute. If the Printer object supports this attribute then it MUST be returned in the
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response. If this attribute is not returned in the response, the client can assume that the "number-of-intervening-jobs" attribute is not supported and will not be returned in a subsequent Job object query.
Note: Since any printer state information which affects a job's state is reflected in the "job-state" and "job-state-reasons" attributes, it is sufficient to return only these attributes and no specific printer status attributes.
Note: In addition to the MANDATORY parameters required for every operation response, the simplest response consists of the just the "attributes-charset" and "attributes-natural-language" operation attributes and the "job-uri", "job-id", and "job-state" Job Object Attributes. In this simplest case, the status code is 'successful- ok' and there is no "status-message" or "detailed-status-message" operation attribute.
This OPTIONAL operation is identical to the Print-Job operation (section 3.2.1) except that a client supplies a URI reference to the document data using the "document-uri" (uri) operation attribute (in Group 1) rather than including the document data itself. Before returning the response, the Printer MUST validate that the Printer supports the retrieval method (e.g., http, ftp, etc.) implied by the URI, and MUST check for valid URI syntax. If the client-supplied URI scheme is not supported, i.e. the value is not in the Printer object's "referenced-uri-scheme-supported" attribute, the Printer object MUST reject the request and return the 'client-error-uri- scheme-not-supported' status code.
The IPP Printer MAY validate the accessibility of the document as part of the operation or subsequently. If the Printer determines an accessibility problem before returning an operation response, it rejects the request and returns the 'client-error-document-access- error' status code. The Printer MAY also return a specific document access error code using the "document-access-error" operation attribute (see section 3.1.6.4).
If the Printer determines this document accessibility problem after accepting the request and returning an operation response with one of the successful status codes, the Printer adds the 'document-access- error' value to the job's "job-state-reasons" attribute and MAY populate the job's "job-document-access-errors" Job Description attribute (see section 4.3.11). See The Implementer's Guide [IPP- IIG] for suggested additional checks.
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If the Printer object supports this operation, it MUST support the "reference-uri-schemes-supported" Printer attribute (see section 4.4.27).
It is up to the IPP object to interpret the URI and subsequently "pull" the document from the source referenced by the URI string.
This REQUIRED operation is similar to the Print-Job operation (section 3.2.1) except that a client supplies no document data and the Printer allocates no resources (i.e., it does not create a new Job object). This operation is used only to verify capabilities of a printer object against whatever attributes are supplied by the client in the Validate-Job request. By using the Validate-Job operation a client can validate that an identical Print-Job operation (with the document data) would be accepted. The Validate-Job operation also performs the same security negotiation as the Print-Job operation (see section 8), so that a client can check that the client and Printer object security requirements can be met before performing a Print-Job operation.
The Validate-Job operation does not accept a "document-uri" attribute in order to allow a client to check that the same Print-URI operation will be accepted, since the client doesn't send the data with the Print-URI operation. The client SHOULD just issue the Print-URI request.
The Printer object returns the same status codes, Operation Attributes (Group 1) and Unsupported Attributes (Group 2) as the Print-Job operation. However, no Job Object Attributes (Group 3) are returned, since no Job object is created.
This OPTIONAL operation is similar to the Print-Job operation (section 3.2.1) except that in the Create-Job request, a client does not supply document data or any reference to document data. Also, the client does not supply any of the "document-name", "document- format", "compression", or "document-natural-language" operation attributes. This operation is followed by one or more Send-Document or Send-URI operations. In each of those operation requests, the client OPTIONALLY supplies the "document-name", "document-format", and "document-natural-language" attributes for each document in the multi-document Job object.
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If a Printer object supports the Create-Job operation, it MUST also support the Send-Document operation and also MAY support the Send-URI operation.
If the Printer object supports this operation, it MUST support the "multiple-operation-time-out" Printer attribute (see section 4.4.31).
If the Printer object supports this operation, then it MUST support the "multiple-document-jobs-supported" Printer Description attribute (see section 4.4.16) and indicate whether or not it supports multiple-document jobs.
If the Printer object supports this operation and supports multiple documents in a job, then it MUST support the "multiple-document- handling" Job Template job attribute with at least one value (see section 4.2.4) and the associated "multiple-document-handling- default" and "multiple-document-handling-supported" Job Template Printer attributes (see section 4.2).
After the Create-Job operation has completed, the value of the "job- state" attribute is similar to the "job-state" after a Print-Job, even though no document-data has arrived. A Printer MAY set the 'job-data-insufficient' value of the job's "job-state-reason" attribute to indicate that processing cannot begin until sufficient data has arrived and set the "job-state" to either 'pending' or 'pending-held'. A non-spooling printer that doesn't implement the 'pending' job state may even set the "job-state" to 'processing', even though there is not yet any data to process. See sections 4.3.7 and 4.3.8.
This REQUIRED operation allows a client to request the values of the attributes of a Printer object. In the request, the client supplies the set of Printer attribute names and/or attribute group names in which the requester is interested. In the response, the Printer object returns a corresponding attribute set with the appropriate attribute values filled in.
For Printer objects, the possible names of attribute groups are:
- 'job-template': the subset of the Job Template attributes that apply to a Printer object (the last two columns of the table in Section 4.2) that the implementation supports for Printer objects. - 'printer-description': the subset of the attributes specified in Section 4.4 that the implementation supports for Printer objects.
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- 'all': the special group 'all' that includes all attributes that the implementation supports for Printer objects.
Since a client MAY request specific attributes or named groups, there is a potential that there is some overlap. For example, if a client requests, 'printer-name' and 'all', the client is actually requesting the "printer-name" attribute twice: once by naming it explicitly, and once by inclusion in the 'all' group. In such cases, the Printer object NEED NOT return each attribute only once in the response even if it is requested multiple times. The client SHOULD NOT request the same attribute in multiple ways.
It is NOT REQUIRED that a Printer object support all attributes belonging to a group (since some attributes are OPTIONAL). However, it is REQUIRED that each Printer object support all group names.
The following sets of attributes are part of the Get-Printer- Attributes Request:
Group 1: Operation Attributes
Natural Language and Character Set: The "attributes-charset" and "attributes-natural-language" attributes as described in section 3.1.4.1.
Target: The "printer-uri" (uri) operation attribute which is the target for this operation as described in section 3.1.5.
Requesting User Name: The "requesting-user-name" (name(MAX)) attribute SHOULD be supplied by the client as described in section 8.3.
"requested-attributes" (1setOf keyword): The client OPTIONALLY supplies a set of attribute names and/or attribute group names in whose values the requester is interested. The Printer object MUST support this attribute. If the client omits this attribute, the Printer MUST respond as if this attribute had been supplied with a value of 'all'.
"document-format" (mimeMediaType): The client OPTIONALLY supplies this attribute. The Printer object MUST support this attribute. This attribute is useful for a Printer object to determine the set of supported attribute values that relate to the requested document format. The Printer object MUST return the attributes and values that
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it uses to validate a job on a create or Validate-Job operation in which this document format is supplied. The Printer object SHOULD return only (1) those attributes that are supported for the specified format and (2) the attribute values that are supported for the specified document format. By specifying the document format, the client can get the Printer object to eliminate the attributes and values that are not supported for a specific document format. For example, a Printer object might have multiple interpreters to support both 'application/postscript' (for PostScript) and 'text/plain' (for text) documents. However, for only one of those interpreters might the Printer object be able to support "number-up" with values of '1', '2', and '4'. For the other interpreter it might be able to only support "number-up" with a value of '1'. Thus a client can use the Get-Printer-Attributes operation to obtain the attributes and values that will be used to accept/reject a create job operation.
If the Printer object does not distinguish between different sets of supported values for each different document format when validating jobs in the create and Validate-Job operations, it MUST NOT distinguish between different document formats in the Get-Printer-Attributes operation. If the Printer object does distinguish between different sets of supported values for each different document format specified by the client, this specialization applies only to the following Printer object attributes:
- Printer attributes that are Job Template attributes ("xxx- default" "xxx-supported", and "xxx-ready" in the Table in Section 4.2), - "pdl-override-supported", - "compression-supported", - "job-k-octets-supported", - "job-impressions-supported", - "job-media-sheets-supported", - "printer-driver-installer", - "color-supported", and - "reference-uri-schemes-supported"
The values of all other Printer object attributes (including "document-format-supported") remain invariant with respect to the client supplied document format (except for new Printer description attribute as registered according to section 6.2).
If the client omits this "document-format" operation attribute, the Printer object MUST respond as if the attribute had been supplied with the value of the Printer object's "document-format-
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default" attribute. It is RECOMMENDED that the client always supply a value for "document-format", since the Printer object's "document-format-default" may be 'application/octet-stream', in which case the returned attributes and values are for the union of the document formats that the Printer can automatically sense. For more details, see the description of the 'mimeMediaType' attribute syntax in section 4.1.9.
If the client supplies a value for the "document-format" Operation attribute that is not supported by the Printer, i.e., is not among the values of the Printer object's "document-format-supported" attribute, the Printer object MUST reject the operation and return the 'client-error-document-format-not-supported' status code.
The Printer object returns the following sets of attributes as part of the Get-Printer-Attributes Response:
Group 1: Operation Attributes
Status Message: In addition to the REQUIRED status code returned in every response, the response OPTIONALLY includes a "status-message" (text(255)) and/or a "detailed-status-message" (text(MAX)) operation attribute as described in sections 13 and 3.1.6.
Natural Language and Character Set: The "attributes-charset" and "attributes-natural-language" attributes as described in section 3.1.4.2.
Group 2: Unsupported Attributes
See section 3.1.7 for details on returning Unsupported Attributes.
The response NEED NOT contain the "requested-attributes" operation attribute with any supplied values (attribute keywords) that were requested by the client but are not supported by the IPP object. If the Printer object does return unsupported attributes referenced in the "requested-attributes" operation attribute and that attribute included group names, such as 'all', the unsupported attributes MUST NOT include attributes described in the standard but not supported by the implementation.
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Group 3: Printer Object Attributes
This is the set of requested attributes and their current values. The Printer object ignores (does not respond with) any requested attribute which is not supported. The Printer object MAY respond with a subset of the supported attributes and values, depending on the security policy in force. However, the Printer object MUST respond with the 'unknown' value for any supported attribute (including all REQUIRED attributes) for which the Printer object does not know the value. Also the Printer object MUST respond with the 'no-value' for any supported attribute (including all REQUIRED attributes) for which the system administrator has not configured a value. See the description of the "out-of-band" values in the beginning of Section 4.1.
This REQUIRED operation allows a client to retrieve the list of Job objects belonging to the target Printer object. The client may also supply a list of Job attribute names and/or attribute group names. A group of Job object attributes will be returned for each Job object that is returned.
This operation is similar to the Get-Job-Attributes operation, except that this Get-Jobs operation returns attributes from possibly more than one object.
The client submits the Get-Jobs request to a Printer object.
The following groups of attributes are part of the Get-Jobs Request:
Group 1: Operation Attributes
Natural Language and Character Set: The "attributes-charset" and "attributes-natural-language" attributes as described in section 3.1.4.1.
Target: The "printer-uri" (uri) operation attribute which is the target for this operation as described in section 3.1.5.
Requesting User Name: The "requesting-user-name" (name(MAX)) attribute SHOULD be supplied by the client as described in section 8.3.
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"limit" (integer(1:MAX)): The client OPTIONALLY supplies this attribute. The Printer object MUST support this attribute. It is an integer value that determines the maximum number of jobs that a client will receive from the Printer even if "which-jobs" or "my-jobs" constrain which jobs are returned. The limit is a "stateless limit" in that if the value supplied by the client is 'N', then only the first 'N' jobs are returned in the Get-Jobs Response. There is no mechanism to allow for the next 'M' jobs after the first 'N' jobs. If the client does not supply this attribute, the Printer object responds with all applicable jobs.
"requested-attributes" (1setOf type2 keyword): The client OPTIONALLY supplies this attribute. The Printer object MUST support this attribute. It is a set of Job attribute names and/or attribute groups names in whose values the requester is interested. This set of attributes is returned for each Job object that is returned. The allowed attribute group names are the same as those defined in the Get-Job-Attributes operation in section 3.3.4. If the client does not supply this attribute, the Printer MUST respond as if the client had supplied this attribute with two values: 'job- uri' and 'job-id'.
"which-jobs" (type2 keyword): The client OPTIONALLY supplies this attribute. The Printer object MUST support this attribute. It indicates which Job objects MUST be returned by the Printer object. The values for this attribute are:
'completed': This includes any Job object whose state is 'completed', 'canceled', or 'aborted'. 'not-completed': This includes any Job object whose state is 'pending', 'processing', 'processing-stopped', or 'pending- held'.
A Printer object MUST support both values. However, if the implementation does not keep jobs in the 'completed', 'canceled', and 'aborted' states, then it returns no jobs when the 'completed' value is supplied.
If a client supplies some other value, the Printer object MUST copy the attribute and the unsupported value to the Unsupported Attributes response group, reject the request, and return the 'client-error-attributes-or-values-not-supported' status code.
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If the client does not supply this attribute, the Printer object MUST respond as if the client had supplied the attribute with a value of 'not-completed'.
"my-jobs" (boolean): The client OPTIONALLY supplies this attribute. The Printer object MUST support this attribute. It indicates whether jobs from all users or just the jobs submitted by the requesting user of this request MUST be considered as candidate jobs to be returned by the Printer object. If the client does not supply this attribute, the Printer object MUST respond as if the client had supplied the attribute with a value of 'false', i.e., jobs from all users. The means for authenticating the requesting user and matching the jobs is described in section 8.
The Printer object returns all of the Job objects up to the number specified by the "limit" attribute that match the criteria as defined by the attribute values supplied by the client in the request. It is possible that no Job objects are returned since there may literally be no Job objects at the Printer, or there may be no Job objects that match the criteria supplied by the client. If the client requests any Job attributes at all, there is a set of Job Object Attributes returned for each Job object.
It is not an error for the Printer to return 0 jobs. If the response returns 0 jobs because there are no jobs matching the criteria, and the request would have returned 1 or more jobs with a status code of 'successful-ok' if there had been jobs matching the criteria, then the status code for 0 jobs MUST be 'successful-ok'.
Group 1: Operation Attributes
Status Message: In addition to the REQUIRED status code returned in every response, the response OPTIONALLY includes a "status-message" (text(255)) and/or a "detailed-status-message" (text(MAX)) operation attribute as described in sections 13 and 3.1.6.
Natural Language and Character Set: The "attributes-charset" and "attributes-natural-language" attributes as described in section 3.1.4.2.
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Group 2: Unsupported Attributes
See section 3.1.7 for details on returning Unsupported Attributes.
The response NEED NOT contain the "requested-attributes" operation attribute with any supplied values (attribute keywords) that were requested by the client but are not supported by the IPP object. If the Printer object does return unsupported attributes referenced in the "requested-attributes" operation attribute and that attribute included group names, such as 'all', the unsupported attributes MUST NOT include attributes described in the standard but not supported by the implementation.
Groups 3 to N: Job Object Attributes
The Printer object responds with one set of Job Object Attributes for each returned Job object. The Printer object ignores (does not respond with) any requested attribute or value which is not supported or which is restricted by the security policy in force, including whether the requesting user is the user that submitted the job (job originating user) or not (see section 8). However, the Printer object MUST respond with the 'unknown' value for any supported attribute (including all REQUIRED attributes) for which the Printer object does not know the value, unless it would violate the security policy. See the description of the "out-of- band" values in the beginning of Section 4.1.
Jobs are returned in the following order:
- If the client requests all 'completed' Jobs (Jobs in the 'completed', 'aborted', or 'canceled' states), then the Jobs are returned newest to oldest (with respect to actual completion time) - If the client requests all 'not-completed' Jobs (Jobs in the 'pending', 'processing', 'pending-held', and 'processing- stopped' states), then Jobs are returned in relative chronological order of expected time to complete (based on whatever scheduling algorithm is configured for the Printer object).
This OPTIONAL operation allows a client to stop the Printer object from scheduling jobs on all its devices. Depending on implementation, the Pause-Printer operation MAY also stop the Printer from processing the current job or jobs. Any job that is currently being printed is either stopped as soon as the implementation permits
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or is completed, depending on implementation. The Printer object MUST still accept create operations to create new jobs, but MUST prevent any jobs from entering the 'processing' state.
If the Pause-Printer operation is supported, then the Resume-Printer operation MUST be supported, and vice-versa.
The IPP Printer stops the current job(s) on its device(s) that were in the 'processing' or 'processing-stopped' states as soon as the implementation permits. If the implementation will take appreciable time to stop, the IPP Printer adds the 'moving-to-paused' value to the Printer object's "printer-state-reasons" attribute (see section 4.4.12). When the device(s) have all stopped, the IPP Printer transitions the Printer object to the 'stopped' state, removes the 'moving-to-paused' value, if present, and adds the 'paused' value to the Printer object's "printer-state-reasons" attribute.
When the current job(s) complete that were in the 'processing' state, the IPP Printer transitions them to the 'completed' state. When the current job(s) stop in mid processing that were in the 'processing' state, the IPP Printer transitions them to the 'processing-stopped' state and adds the 'printer-stopped' value to the job's "job-state- reasons" attribute.
For any jobs that are 'pending' or 'pending-held', the 'printer- stopped' value of the jobs' "job-state-reasons" attribute also applies. However, the IPP Printer NEED NOT update those jobs' "job- state-reasons" attributes and only need return the 'printer-stopped' value when those jobs are queried (so-called "lazy evaluation").
Whether the Pause-Printer operation affects jobs that were submitted to the device from other sources than the IPP Printer object in the same way that the Pause-Printer operation affects jobs that were submitted to the IPP Printer object using IPP, depends on implementation, i.e., on whether the IPP protocol is being used as a universal management protocol or just to manage IPP jobs, respectively.
The IPP Printer MUST accept the request in any state and transition the Printer to the indicated new "printer-state" before returning as follows:
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Current New "printer IPP Printer's response status "printer- "printer- -state- code and action: state" state" reasons"
'idle' 'stopped' 'paused' 'successful-ok' 'processing' 'processing' 'moving- OPTION 1: 'successful-ok'; to- Later, when all output has paused' stopped, the "printer-state" becomes 'stopped', and the 'paused' value replaces the 'moving-to-paused' value in the "printer-state-reasons" attribute 'processing' 'stopped' 'paused' OPTION 2: 'successful-ok'; all device output stopped immediately 'stopped' 'stopped' 'paused' 'successful-ok'
Access Rights: The authenticated user (see section 8.3) performing this operation must be an operator or administrator of the Printer object (see Sections 1 and 8.5). Otherwise, the IPP Printer MUST reject the operation and return: 'client-error-forbidden', 'client- error-not-authenticated', or 'client-error-not-authorized' as appropriate.
The following groups of attributes are part of the Pause-Printer Response:
Group 1: Operation Attributes
Status Message: In addition to the REQUIRED status code returned in every response, the response OPTIONALLY includes a "status-message" (text(255)) and/or a "detailed-status-message" (text(MAX)) operation attribute as described in sections 13 and 3.1.6.
Natural Language and Character Set: The "attributes-charset" and "attributes-natural-language" attributes as described in section 3.1.4.2.
Group 2: Unsupported Attributes
See section 3.1.7 for details on returning Unsupported Attributes.
This operation allows a client to resume the Printer object scheduling jobs on all its devices. The Printer object MUST remove the 'paused' and 'moving-to-paused' values from the Printer object's "printer-state-reasons" attribute, if present. If there are no other reasons to keep a device paused (such as media-jam), the IPP Printer is free to transition itself to the 'processing' or 'idle' states, depending on whether there are jobs to be processed or not, respectively, and the device(s) resume processing jobs.
If the Pause-Printer operation is supported, then the Resume-Printer operation MUST be supported, and vice-versa.
The IPP Printer removes the 'printer-stopped' value from any job's "job-state-reasons" attributes contained in that Printer.
The IPP Printer MUST accept the request in any state, transition the Printer object to the indicated new state as follows:
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Current New "printer- IPP Printer's response status code and "printer- state" action: state"
'stopped' 'processing' 'successful-ok'; when there are jobs to be processed 'stopped' 'idle' 'successful-ok'; when there are no jobs to be processed.
Access Rights: The authenticated user (see section 8.3) performing this operation must be an operator or administrator of the Printer object (see Sections 1 and 8.5). Otherwise, the IPP Printer MUST reject the operation and return: 'client-error-forbidden', 'client- error-not-authenticated', or 'client-error-not-authorized' as appropriate.
The Resume-Printer Request and Resume-Printer Response have the same attribute groups and attributes as the Pause-Printer operation (see sections 3.2.7.1 and 3.2.7.2).
This OPTIONAL operation allows a client to remove all jobs from an IPP Printer object, regardless of their job states, including jobs in the Printer object's Job History (see Section 4.3.7.2). After a Purge-Jobs operation has been performed, a Printer object MUST return no jobs in subsequent Get-Job-Attributes and Get-Jobs responses (until new jobs are submitted).
Whether the Purge-Jobs (and Get-Jobs) operation affects jobs that were submitted to the device from other sources than the IPP Printer object in the same way that the Purge-Jobs operation affects jobs that were submitted to the IPP Printer object using IPP, depends on implementation, i.e., on whether the IPP protocol is being used as a universal management protocol or just to manage IPP jobs, respectively.
Note: if an operator wants to cancel all jobs without clearing out the Job History, the operator uses the Cancel-Job operation on each job instead of using the Purge-Jobs operation.
The Printer object MUST accept this operation in any state and transition the Printer object to the 'idle' state.
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Access Rights: The authenticated user (see section 8.3) performing this operation must be an operator or administrator of the Printer object (see Sections 1 and 8.5). Otherwise, the IPP object MUST reject the operation and return: client-error-forbidden, client- error-not-authenticated, and client-error-not-authorized as appropriate.
The Purge-Jobs Request and Purge-Jobs Response have the same attribute groups and attributes as the Pause-Printer operation (see sections 3.2.7.1 and 3.2.7.2).
All Job operations are directed at Job objects. A client MUST always supply some means of identifying the Job object in order to identify the correct target of the operation. That job identification MAY either be a single Job URI or a combination of a Printer URI with a Job ID. The IPP object implementation MUST support both forms of identification for every job.
This OPTIONAL operation allows a client to create a multi-document Job object that is initially "empty" (contains no documents). In the Create-Job response, the Printer object returns the Job object's URI (the "job-uri" attribute) and the Job object's 32-bit identifier (the "job-id" attribute). For each new document that the client desires to add, the client uses a Send-Document operation. Each Send- Document Request contains the entire stream of document data for one document.
If the Printer supports this operation but does not support multiple documents per job, the Printer MUST reject subsequent Send-Document operations supplied with data and return the 'server-error-multiple- document-jobs-not-supported'. However, the Printer MUST accept the first document with a 'true' or 'false' value for the "last-document" operation attribute (see below), so that clients MAY always submit one document jobs with a 'false' value for "last-document" in the first Send-Document and a 'true' for "last-document" in the second Send-Document (with no data).
Since the Create-Job and the send operations (Send-Document or Send- URI operations) that follow could occur over an arbitrarily long period of time for a particular job, a client MUST send another send operation within an IPP Printer defined minimum time interval after the receipt of the previous request for the job. If a Printer object supports the Create-Job and Send-Document operations, the Printer object MUST support the "multiple-operation-time-out" attribute (see
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section 4.4.31). This attribute indicates the minimum number of seconds the Printer object will wait for the next send operation before taking some recovery action.
An IPP object MUST recover from an errant client that does not supply a send operation, sometime after the minimum time interval specified by the Printer object's "multiple-operation-time-out" attribute. Such recovery MAY include any of the following or other recovery actions:
1. Assume that the Job is an invalid job, start the process of changing the job state to 'aborted', add the 'aborted-by- system' value to the job's "job-state-reasons" attribute (see section 4.3.8), and clean up all resources associated with the Job. In this case, if another send operation is finally received, the Printer responds with an "client-error-not- possible" or "client-error-not-found" depending on whether or not the Job object is still around when the send operation finally arrives. 2. Assume that the last send operation received was in fact the last document (as if the "last-document" flag had been set to 'true'), close the Job object, and proceed to process it (i.e., move the Job's state to 'pending'). 3. Assume that the last send operation received was in fact the last document, close the Job, but move it to the 'pending-held' and add the 'submission-interrupted' value to the job's "job- state-reasons" attribute (see section 4.3.8). This action allows the user or an operator to determine whether to continue processing the Job by moving it back to the 'pending' state using the Release-Job operation (see section 3.3.6) or to cancel the job using the Cancel-Job operation (see section 3.3.3).
Each implementation is free to decide the "best" action to take depending on local policy, whether any documents have been added, whether the implementation spools jobs or not, and/or any other piece of information available to it. If the choice is to abort the Job object, it is possible that the Job object may already have been processed to the point that some media sheet pages have been printed.
Access Rights: The authenticated user (see section 8.3) performing this operation must either be the job owner (as determined in the Create-Job operation) or an operator or administrator of the Printer object (see Sections 1 and 8.5). Otherwise, the IPP object MUST reject the operation and return: 'client-error-forbidden', 'client- error-not-authenticated', or 'client-error-not-authorized' as appropriate.
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The following attribute sets are part of the Send-Document Request:
Group 1: Operation Attributes
Natural Language and Character Set: The "attributes-charset" and "attributes-natural-language" attributes as described in section 3.1.4.1.
Target: Either (1) the "printer-uri" (uri) plus "job-id" (integer(1:MAX))or (2) the "job-uri" (uri) operation attribute(s) which define the target for this operation as described in section 3.1.5.
Requesting User Name: The "requesting-user-name" (name(MAX)) attribute SHOULD be supplied by the client as described in section 8.3.
"document-name" (name(MAX)): The client OPTIONALLY supplies this attribute. The Printer object MUST support this attribute. It contains the client supplied document name. The document name MAY be different than the Job name. It might be helpful, but NEED NOT be unique across multiple documents in the same Job. Typically, the client software automatically supplies the document name on behalf of the end user by using a file name or an application generated name. See the description of the "document-name" operation attribute in the Print-Job Request (section 3.2.1.1) for more information about this attribute.
"compression" (type3 keyword): See the description of "compression" for the Print-Job operation in Section 3.2.1.1.
"document-format" (mimeMediaType): See the description of "document-format" for the Print-Job operation in Section 3.2.1.1.
"document-natural-language" (naturalLanguage): The client OPTIONALLY supplies this attribute. The Printer object OPTIONALLY supports this attribute. This attribute specifies the natural language of the document for those document-formats that require a specification of the natural language in order to image the document unambiguously. There are no particular values required for the Printer object to support.
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"last-document" (boolean): The client MUST supply this attribute. The Printer object MUST support this attribute. It is a boolean flag that is set to 'true' if this is the last document for the Job, 'false' otherwise.
Group 2: Document Content
The client MUST supply the document data if the "last-document" flag is set to 'false'. However, since a client might not know that the previous document sent with a Send-Document (or Send-URI) operation was the last document (i.e., the "last-document" attribute was set to 'false'), it is legal to send a Send-Document request with no document data where the "last-document" flag is set to 'true'. Such a request MUST NOT increment the value of the Job object's "number-of-documents" attribute, since no real document was added to the job. It is not an error for a client to submit a job with no actual document data, i.e., only a single Create-Job and Send-Document request with a "last-document" operation attribute set to 'true' with no document data.
The following sets of attributes are part of the Send-Document Response:
Group 1: Operation Attributes
Status Message: In addition to the REQUIRED status code returned in every response, the response OPTIONALLY includes a "status-message" (text(255)) and/or a "detailed-status-message" (text(MAX)) operation attribute as described in sections 13 and 3.1.6.
Natural Language and Character Set: The "attributes-charset" and "attributes-natural-language" attributes as described in section 3.1.4.2.
Group 2: Unsupported Attributes
See section 3.1.7 for details on returning Unsupported Attributes.
Group 3: Job Object Attributes
This is the same set of attributes as described in the Print-Job response (see section 3.2.1.2).
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This OPTIONAL operation is identical to the Send-Document operation (see section 3.3.1) except that a client MUST supply a URI reference ("document-uri" operation attribute) rather than the document data itself. If a Printer object supports this operation, clients can use both Send-URI or Send-Document operations to add new documents to an existing multi-document Job object. However, if a client needs to indicate that the previous Send-URI or Send-Document was the last document, the client MUST use the Send-Document operation with no document data and the "last-document" flag set to 'true' (rather than using a Send-URI operation with no "document-uri" operation attribute).
If a Printer object supports this operation, it MUST also support the Print-URI operation (see section 3.2.2).
The Printer object MUST validate the syntax and URI scheme of the supplied URI before returning a response, just as in the Print-URI operation. The IPP Printer MAY validate the accessibility of the document as part of the operation or subsequently (see section 3.2.2).
This REQUIRED operation allows a client to cancel a Print Job from the time the job is created up to the time it is completed, canceled, or aborted. Since a Job might already be printing by the time a Cancel-Job is received, some media sheet pages might be printed before the job is actually terminated.
The IPP object MUST accept or reject the request based on the job's current state and transition the job to the indicated new state as follows:
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Current "job- New "job- IPP object's response status state" state" code and action:
Rule 1: If the implementation requires some measurable time to cancel the job in the 'processing' or 'processing-stopped' job states, the IPP object MUST add the 'processing-to-stop-point' value to the job's "job-state-reasons" attribute and then transition the job to the 'canceled' state when the processing ceases (see section 4.3.8).
Rule 2: If the Job object already has the 'processing-to-stop-point' value in its "job-state-reasons" attribute, then the Printer object MUST reject a Cancel-Job operation.
Access Rights: The authenticated user (see section 8.3) performing this operation must either be the job owner or an operator or administrator of the Printer object (see Sections 1 and 8.5). Otherwise, the IPP object MUST reject the operation and return: 'client-error-forbidden', 'client-error-not-authenticated', or 'client-error-not-authorized' as appropriate.
The following groups of attributes are part of the Cancel-Job Request:
Group 1: Operation Attributes
Natural Language and Character Set: The "attributes-charset" and "attributes-natural-language" attributes as described in section 3.1.4.1.
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Target: Either (1) the "printer-uri" (uri) plus "job-id" (integer(1:MAX))or (2) the "job-uri" (uri) operation attribute(s) which define the target for this operation as described in section 3.1.5.
Requesting User Name: The "requesting-user-name" (name(MAX)) attribute SHOULD be supplied by the client as described in section 8.3.
"message" (text(127)): The client OPTIONALLY supplies this attribute. The Printer object OPTIONALLY supports this attribute. It is a message to the operator. This "message" attribute is not the same as the "job-message-from-operator" attribute. That attribute is used to report a message from the operator to the end user that queries that attribute. This "message" operation attribute is used to send a message from the client to the operator along with the operation request. It is an implementation decision of how or where to display this message to the operator (if at all).
The following sets of attributes are part of the Cancel-Job Response:
Group 1: Operation Attributes
Status Message: In addition to the REQUIRED status code returned in every response, the response OPTIONALLY includes a "status-message" (text(255)) and/or a "detailed-status-message" (text(MAX)) operation attribute as described in sections 13 and 3.1.6.
Natural Language and Character Set: The "attributes-charset" and "attributes-natural-language" attributes as described in section 3.1.4.2.
Group 2: Unsupported Attributes
See section 3.1.7 for details on returning Unsupported Attributes.
Once a successful response has been sent, the implementation guarantees that the Job will eventually end up in the 'canceled' state. Between the time of the Cancel-Job operation is accepted and when the job enters the 'canceled' job-state (see section 4.3.7), the "job-state-reasons" attribute SHOULD contain the 'processing-to- stop-point'
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value which indicates to later queries that although the Job might still be 'processing', it will eventually end up in the 'canceled' state, not the 'completed' state.
This REQUIRED operation allows a client to request the values of attributes of a Job object and it is almost identical to the Get- Printer-Attributes operation (see section 3.2.5). The only differences are that the operation is directed at a Job object rather than a Printer object, there is no "document-format" operation attribute used when querying a Job object, and the returned attribute group is a set of Job object attributes rather than a set of Printer object attributes.
For Jobs, the possible names of attribute groups are:
- 'job-template': the subset of the Job Template attributes that apply to a Job object (the first column of the table in Section 4.2) that the implementation supports for Job objects. - 'job-description': the subset of the Job Description attributes specified in Section 4.3 that the implementation supports for Job objects. - 'all': the special group 'all' that includes all attributes that the implementation supports for Job objects.
Since a client MAY request specific attributes or named groups, there is a potential that there is some overlap. For example, if a client requests, 'job-name' and 'job-description', the client is actually requesting the "job-name" attribute once by naming it explicitly, and once by inclusion in the 'job-description' group. In such cases, the Printer object NEED NOT return the attribute only once in the response even if it is requested multiple times. The client SHOULD NOT request the same attribute in multiple ways.
It is NOT REQUIRED that a Job object support all attributes belonging to a group (since some attributes are OPTIONAL). However it is REQUIRED that each Job object support all these group names.
The following groups of attributes are part of the Get-Job-Attributes Request when the request is directed at a Job object:
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Group 1: Operation Attributes
Natural Language and Character Set: The "attributes-charset" and "attributes-natural-language" attributes as described in section 3.1.4.1.
Target: Either (1) the "printer-uri" (uri) plus "job-id" (integer(1:MAX)) or (2) the "job-uri" (uri) operation attribute(s) which define the target for this operation as described in section 3.1.5.
Requesting User Name: The "requesting-user-name" (name(MAX)) attribute SHOULD be supplied by the client as described in section 8.3.
"requested-attributes" (1setOf keyword): The client OPTIONALLY supplies this attribute. The IPP object MUST support this attribute. It is a set of attribute names and/or attribute group names in whose values the requester is interested. If the client omits this attribute, the IPP object MUST respond as if this attribute had been supplied with a value of 'all'.
The Printer object returns the following sets of attributes as part of the Get-Job-Attributes Response:
Group 1: Operation Attributes
Status Message: In addition to the REQUIRED status code returned in every response, the response OPTIONALLY includes a "status-message" (text(255)) and/or a "detailed-status-message" (text(MAX)) operation attribute as described in sections 13 and 3.1.6.
Natural Language and Character Set: The "attributes-charset" and "attributes-natural-language" attributes as described in section 3.1.4.2. The "attributes- natural-language" MAY be the natural language of the Job object, rather than the one requested.
Group 2: Unsupported Attributes
See section 3.1.7 for details on returning Unsupported Attributes.
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The response NEED NOT contain the "requested-attributes" operation attribute with any supplied values (attribute keywords) that were requested by the client but are not supported by the IPP object. If the Printer object does return unsupported attributes referenced in the "requested-attributes" operation attribute and that attribute included group names, such as 'all', the unsupported attributes MUST NOT include attributes described in the standard but not supported by the implementation.
Group 3: Job Object Attributes
This is the set of requested attributes and their current values. The IPP object ignores (does not respond with) any requested attribute or value which is not supported or which is restricted by the security policy in force, including whether the requesting user is the user that submitted the job (job originating user) or not (see section 8). However, the IPP object MUST respond with the 'unknown' value for any supported attribute (including all REQUIRED attributes) for which the IPP object does not know the value, unless it would violate the security policy. See the description of the "out-of-band" values in the beginning of Section 4.1.
This OPTIONAL operation allows a client to hold a pending job in the queue so that it is not eligible for scheduling. If the Hold-Job operation is supported, then the Release-Job operation MUST be supported, and vice-versa. The OPTIONAL "job-hold-until" operation attribute allows a client to specify whether to hold the job indefinitely or until a specified time period, if supported.
The IPP object MUST accept or reject the request based on the job's current state and transition the job to the indicated new state as follows:
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Current "job- New "job-state" IPP object's response status state" code and action:
Rule 1: If the implementation supports multiple reasons for a job to be in the 'pending-held' state, the IPP object MUST add the 'job- hold-until-specified' value to the job's "job-state-reasons" attribute.
Rule 2: If the IPP object supports the "job-hold-until" operation attribute, but the specified time period has already started (or is the 'no-hold' value) and there are no other reasons to hold the job, the IPP object MUST make the job be a candidate for processing immediately (see Section 4.2.2) by putting the job in the 'pending' state.
Note: In order to keep the Hold-Job operation simple, such a request is rejected when the job is in the 'processing' or 'processing- stopped' states. If an operation is needed to hold jobs while in these states, it will be added as an additional operation, rather than overloading the Hold-Job operation. Then it is clear to clients by querying the Printer object's "operations-supported" (see Section 4.4.15) and the Job object's "job-state" (see Section 4.3.7) attributes which operations are possible.
Access Rights: The authenticated user (see section 8.3) performing this operation must either be the job owner or an operator or administrator of the Printer object (see Sections 1 and 8.5). Otherwise, the IPP object MUST reject the operation and return: 'client-error-forbidden', 'client-error-not-authenticated', or 'client-error-not-authorized' as appropriate.
The groups and operation attributes are the same as for a Cancel-Job request (see section 3.3.3.1), with the addition of the following Group 1 Operation attribute:
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"job-hold-until" (type3 keyword | name(MAX)): The client OPTIONALLY supplies this Operation attribute. The IPP object MUST support this operation attribute in a Hold-Job request, if it supports the "job-hold-until" Job template attribute in create operations. See section 4.2.2. The IPP object SHOULD support the "job-hold-until" Job Template attribute for use in job create operations with at least the 'indefinite' value, if it supports the Hold-Job operation. Otherwise, a client cannot create a job and hold it immediately (without picking some supported time period in the future).
If supplied and supported as specified in the Printer's "job- hold-until-supported" attribute, the IPP object copies the supplied operation attribute to the Job object, replacing the job's previous "job-hold-until" attribute, if present, and makes the job a candidate for scheduling during the supplied named time period.
If supplied, but either the "job-hold-until" Operation attribute itself or the value supplied is not supported, the IPP object accepts the request, returns the unsupported attribute or value in the Unsupported Attributes Group according to section 3.1.7, returns the 'successful-ok- ignored-or-substituted-attributes, and holds the job indefinitely until a client performs a subsequent Release-Job operation.
If the client (1) supplies a value that specifies a time period that has already started or the 'no-hold' value (meaning don't hold the job) and (2) the IPP object supports the "job-hold- until" operation attribute and there are no other reasons to hold the job, the IPP object MUST accept the operation and make the job be a candidate for processing immediately (see Section 4.2.2).
If the client does not supply a "job-hold-until" Operation attribute in the request, the IPP object MUST populate the job object with a "job-hold-until" attribute with the 'indefinite' value (if IPP object supports the "job-hold-until" attribute) and hold the job indefinitely, until a client performs a Release-Job operation.
This OPTIONAL operation allows a client to release a previously held job so that it is again eligible for scheduling. If the Hold-Job operation is supported, then the Release-Job operation MUST be supported, and vice-versa.
This operation removes the "job-hold-until" job attribute, if present, from the job object that had been supplied in the create or most recent Hold-Job or Restart-Job operation and removes its effect on the job. The IPP object MUST remove the 'job-hold-until- specified' value from the job's "job-state-reasons" attribute, if present. See section 4.3.8.
The IPP object MUST accept or reject the request based on the job's current state and transition the job to the indicated new state as follows:
Current "job- New "job-state" IPP object's response status state" code and action:
'pending' 'pending' 'successful-ok' No effect on the job. 'pending-held' 'pending-held' 'successful-ok' See Rule 1 'pending-held' 'pending' 'successful-ok' 'processing' 'processing' 'successful-ok' No effect on the job. 'processing- 'processing- 'successful-ok' stopped' stopped' No effect on the job. 'completed' 'completed' 'client-error-not-possible' 'canceled' 'canceled' 'client-error-not-possible' 'aborted' 'aborted' 'client-error-not-possible'
Rule 1: If there are other reasons to keep the job in the 'pending- held' state, such as 'resources-are-not-ready', the job remains in the 'pending-held' state. Thus the 'pending-held' state is not just for jobs that have the 'job-hold-until' applied to them, but are for any reason to keep the job from being a candidate for scheduling and processing, such as 'resources-are-not-ready'. See the "job-hold- until" attribute (section 4.2.2).
Access Rights: The authenticated user (see section 8.3) performing this operation must either be the job owner or an operator or administrator of the Printer object (see Sections 1 and 8.5). Otherwise, the IPP object MUST reject the operation and return: 'client-error-forbidden', 'client-error-not-authenticated', or 'client-error-not-authorized' as appropriate.
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The Release-Job Request and Release-Job Response have the same attribute groups and attributes as the Cancel-Job operation (see section 3.3.3.1 and 3.3.3.2).
This OPTIONAL operation allows a client to restart a job that is retained in the queue after processing has completed (see section 4.3.7.2).
The job is moved to the 'pending' or 'pending-held' job state and restarts at the beginning on the same IPP Printer object with the same attribute values. If any of the documents in the job were passed by reference (Print-URI or Send-URI), the Printer MUST re- fetch the data, since the semantics of Restart-Job are to repeat all Job processing. The Job Description attributes that accumulate job progress, such as "job-impressions-completed", "job-media-sheets- completed", and "job-k-octets-processed", MUST be reset to 0 so that they give an accurate record of the job from its restart point. The job object MUST continue to use the same "job-uri" and "job-id" attribute values.
Note: If in the future an operation is needed that does not reset the job progress attributes, then a new operation will be defined which makes a copy of the job, assigns a new "job-uri" and "job-id" to the copy and resets the job progress attributes in the new copy only.
The IPP object MUST accept or reject the request based on the job's current state, transition the job to the indicated new state as follows:
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Current "job- New "job-state" IPP object's response status state" code and action:
'pending' 'pending' 'client-error-not-possible' 'pending-held' 'pending-held' 'client-error-not-possible' 'processing' 'processing' 'client-error-not-possible' 'processing- 'processing- 'client-error-not-possible' stopped' stopped' 'completed' 'pending' or 'successful-ok' - job is started 'pending-held' over. 'completed' 'completed' 'client-error-not-possible' - see Rule 1 'canceled' 'pending' or 'successful-ok' - job is started 'pending-held' over. 'canceled' 'canceled' 'client-error-not-possible' - see Rule 1 'aborted' 'pending' or 'successful-ok' - job is started 'pending-held' over. 'aborted' 'aborted' 'client-error-not-possible' - see Rule 1
Rule 1: If the Job Retention Period has expired for the job in this state, then the IPP object rejects the operation. See section 4.3.7.2.
Note: In order to prevent a user from inadvertently restarting a job in the middle, the Restart-Job request is rejected when the job is in the 'processing' or 'processing-stopped' states. If in the future an operation is needed to hold or restart jobs while in these states, it will be added as an additional operation, rather than overloading the Restart-Job operation, so that it is clear that the user intended that the current job not be completed.
Access Rights: The authenticated user (see section 8.3) performing this operation must either be the job owner or an operator or administrator of the Printer object (see Sections 1 and 8.5). Otherwise, the IPP object MUST reject the operation and return: 'client-error-forbidden', 'client-error-not-authenticated', or 'client-error-not-authorized' as appropriate.
The groups and attributes are the same as for a Cancel-Job request (see section 3.3.3.1), with the addition of the following Group 1 Operation attribute:
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"job-hold-until" (type3 keyword | name(MAX)): The client OPTIONALLY supplies this attribute. The IPP object MUST support this Operation attribute in a Restart-Job request, if it supports the "job-hold-until" Job Template attribute in create operations. See section 4.2.2. Otherwise, the IPP object NEED NOT support the "job-hold-until" Operation attribute in a Restart-Job request.
If supplied and supported as specified in the Printer's "job- hold-until-supported" attribute, the IPP object copies the supplied Operation attribute to the Job object, replacing the job's previous "job-hold-until" attribute, if present, and makes the job a candidate for scheduling during the supplied named time period. See section 4.2.2.
If supplied, but the value is not supported, the IPP object accepts the request, returns the unsupported attribute or value in the Unsupported Attributes Group according to section 3.1.7, returns the 'successful-ok-ignored-or-substituted-attributes' status code, and holds the job indefinitely until a client performs a subsequent Release-Job operation.
If supplied, but the "job-hold-until" Operation attribute itself is not supported, the IPP object accepts the request, returns the unsupported attribute with the out-of-band 'unsupported' value in the Unsupported Attributes Group according to section 3.1.7, returns the 'successful-ok- ignored-or-substituted-attributes' status code, and restarts the job, i.e., ignores the "job-hold-until" attribute.
If the client (1) supplies a value that specifies a time period that has already started or the 'no-hold' value (meaning don't hold the job) and (2) the IPP object supports the "job-hold- until" operation attribute and there are no other reasons to hold the job, the IPP object makes the job a candidate for processing immediately (see Section 4.2.2).
If the client does not supply a "job-hold-until" operation attribute in the request, the IPP object removes the "job- hold-until" attribute, if present, from the job. If there are no other reasons to hold the job, the Restart-Job operation makes the job a candidate for processing immediately (see Section 4.2.2).
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The groups and attributes are the same as for a Cancel-Job response (see section 3.3.3.2).
Note: In the future an OPTIONAL Modify-Job or Set-Job-Attributes operation may be specified that allows the client to modify other attributes before releasing the restarted job.
This section describes the attributes with their corresponding attribute syntaxes and values that are part of the IPP model. The sections below show the objects and their associated attributes which are included within the scope of this protocol. Many of these attributes are derived from other relevant documents:
Each attribute is uniquely identified in this document using a "keyword" (see section 12.2.1) which is the name of the attribute. The keyword is included in the section header describing that attribute.
Note: Not only are keywords used to identify attributes, but one of the attribute syntaxes described below is "keyword" so that some attributes have keyword values. Therefore, these attributes are defined as having an attribute syntax that is a set of keywords.
This section defines the basic attribute syntax types that all clients and IPP objects MUST be able to accept in responses and accept in requests, respectively. Each attribute description in sections 3 and 4 includes the name of attribute syntax(es) in the heading (in parentheses). A conforming implementation of an attribute MUST include the semantics of the attribute syntax(es) so identified. Section 6.3 describes how the protocol can be extended with new attribute syntaxes.
The attribute syntaxes are specified in the following sub-sections, where the sub-section heading is the keyword name of the attribute syntax inside the single quotes. In operation requests and responses each attribute value MUST be represented as one of the attribute syntaxes specified in the sub-section heading for the attribute. In addition, the value of an attribute in a response (but not in a
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request) MAY be one of the "out-of-band" values whose special encoding rules are defined in the "Encoding and Transport" document [RFC2910]. Standard "out-of-band" values are:
'unknown': The attribute is supported by the IPP object, but the value is unknown to the IPP object for some reason. 'unsupported': The attribute is unsupported by the IPP object. This value MUST be returned only as the value of an attribute in the Unsupported Attributes Group. 'no-value': The attribute is supported by the Printer object, but the administrator has not yet configured a value.
All attributes in a request MUST have one or more values as defined in Sections 4.2 to 4.4. Thus clients MUST NOT supply attributes with "out-of-band" values for operations defined in this document. All attributes in a response MUST have one or more values as defined in Sections 4.2 to 4.4 or a single "out-of-band" value.
Most attributes are defined to have a single attribute syntax. However, a few attributes (e.g., "job-sheet", "media", "job-hold- until") are defined to have several attribute syntaxes, depending on the value. These multiple attribute syntaxes are separated by the "|" character in the sub-section heading to indicate the choice. Since each value MUST be tagged as to its attribute syntax in the protocol, a single-valued attribute instance may have any one of its attribute syntaxes and a multi-valued attribute instance may have a mixture of its defined attribute syntaxes.
A text attribute is an attribute whose value is a sequence of zero or more characters encoded in a maximum of 1023 ('MAX') octets. MAX is the maximum length for each value of any text attribute. However, if an attribute will always contain values whose maximum length is much less than MAX, the definition of that attribute will include a qualifier that defines the maximum length for values of that attribute. For example: the "printer-location" attribute is specified as "printer-location (text(127))". In this case, text values for "printer-location" MUST NOT exceed 127 octets; if supplied with a longer text string via some external interface (other than the protocol), implementations are free to truncate to this shorter length limitation.
In this document, all text attributes are defined using the 'text' syntax. However, 'text' is used only for brevity; the formal interpretation of 'text' is: 'textWithoutLanguage | textWithLanguage'. That is, for any attribute defined in this document using the 'text' attribute syntax, all IPP objects and
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clients MUST support both the 'textWithoutLanguage' and 'textWithLanguage' attribute syntaxes. However, in actual usage and protocol execution, objects and clients accept and return only one of the two syntax per attribute. The syntax 'text' never appears "on- the-wire".
Both 'textWithoutLanguage' and 'textWithLanguage' are needed to support the real world needs of interoperability between sites and systems that use different natural languages as the basis for human communication. Generally, one natural language applies to all text attributes in a given request or response. The language is indicated by the "attributes-natural-language" operation attribute defined in section 3.1.4 or "attributes-natural-language" job attribute defined in section 4.3.20, and there is no need to identify the natural language for each text string on a value-by-value basis. In these cases, the attribute syntax 'textWithoutLanguage' is used for text attributes. In other cases, the client needs to supply or the Printer object needs to return a text value in a natural language that is different from the rest of the text values in the request or response. In these cases, the client or Printer object uses the attribute syntax 'textWithLanguage' for text attributes (this is the Natural Language Override mechanism described in section 3.1.4).
The 'textWithoutLanguage' and 'textWithLanguage' attribute syntaxes are described in more detail in the following sections.
The 'textWithoutLanguage' syntax indicates a value that is sequence of zero or more characters encoded in a maximum of 1023 (MAX) octets. Text strings are encoded using the rules of some charset. The Printer object MUST support the UTF-8 charset [RFC2279] and MAY support additional charsets to represent 'text' values, provided that the charsets are registered with IANA [IANA-CS]. See Section 4.1.7 for the definition of the 'charset' attribute syntax, including restricted semantics and examples of charsets.
The 'textWithLanguage' attribute syntax is a compound attribute syntax consisting of two parts: a 'textWithoutLanguage' part encoded in a maximum of 1023 (MAX) octets plus an additional 'naturalLanguage' (see section 4.1.8) part that overrides the natural language in force. The 'naturalLanguage' part explicitly identifies the natural language that applies to the text part of that value and that value alone. For any give text attribute, the 'textWithoutLanguage' part is limited to the maximum length defined for that 'text' attribute, and the 'naturalLanguage' part is always
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limited to 63 (additional) octets. Using the 'textWithLanguage' attribute syntax rather than the normal 'textWithoutLanguage' syntax is the so-called Natural Language Override mechanism and MUST be supported by all IPP objects and clients.
If the attribute is multi-valued (1setOf text), then the 'textWithLanguage' attribute syntax MUST be used to explicitly specify each attribute value whose natural language needs to be overridden. Other values in a multi-valued 'text' attribute in a request or a response revert to the natural language of the operation attribute.
In a create request, the Printer object MUST accept and store with the Job object any natural language in the "attributes-natural- language" operation attribute, whether the Printer object supports that natural language or not. Furthermore, the Printer object MUST accept and store any 'textWithLanguage' attribute value, whether the Printer object supports that natural language or not. These requirements are independent of the value of the "ipp-attribute- fidelity" operation attribute that the client MAY supply.
Example: If the client supplies the "attributes-natural-language" operation attribute with the value: 'en' indicating English, but the value of the "job-name" attribute is in French, the client MUST use the 'textWithLanguage' attribute syntax with the following two values:
'fr': Natural Language Override indicating French 'Rapport Mensuel': the job name in French
See the "Encoding and Transport" document [RFC2910] section 3.9 for the encoding of the two parts and Appendix A for a detailed example of the 'textWithLanguage' attribute syntax.
This syntax type is used for user-friendly strings, such as a Printer name, that, for humans, are more meaningful than identifiers. Names are never translated from one natural language to another. The 'name' attribute syntax is essentially the same as 'text', including the REQUIRED support of UTF-8 except that the sequence of characters is limited so that its encoded form MUST NOT exceed 255 (MAX) octets.
Also like 'text', 'name' is really an abbreviated notation for either 'nameWithoutLanguage' or 'nameWithLanguage'. That is, all IPP objects and clients MUST support both the 'nameWithoutLanguage' and 'nameWithLanguage' attribute syntaxes. However, in actual usage and
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protocol execution, objects and clients accept and return only one of the two syntax per attribute. The syntax 'name' never appears "on- the-wire".
Only the 'text' and 'name' attribute syntaxes permit the Natural Language Override mechanism.
Some attributes are defined as 'type3 keyword | name'. These attributes support values that are either type3 keywords or names. This dual-syntax mechanism enables a site administrator to extend these attributes to legally include values that are locally defined by the site administrator. Such names are not registered with IANA.
The 'nameWithLanguage' attribute syntax is a compound attribute syntax consisting of two parts: a 'nameWithoutLanguage' part encoded in a maximum of 1023 (MAX) octets plus an additional 'naturalLanguage' (see section 4.1.8) part that overrides the natural language in force. The 'naturalLanguage' part explicitly identifies the natural language that applies to that name value and that name value alone. For any give text attribute, the 'textWithoutLanguage' part is limited to the maximum length defined for that 'text' attribute, and the 'naturalLanguage' part is always limited to 63 (additional) octets. Using the 'textWithLanguage' attribute syntax rather than the normal 'textWithoutLanguage' syntax is the so-called Natural Language Override mechanism and MUST be supported by all IPP objects and clients.
The 'nameWithLanguage' attribute syntax behaves the same as the 'textWithLanguage' syntax. Using the 'textWithLanguage' attribute syntax rather than the normal 'textWithoutLanguage' syntax is the so-called Natural Language Override mechanism and MUST be supported by all IPP objects and clients. If a name is in a language that is different than the rest of the object or operation, then this 'nameWithLanguage' syntax is used rather than the generic 'nameWithoutLanguage' syntax.
If the attribute is multi-valued (1setOf text), then the 'nameWithLanguage' attribute syntax MUST be used to explicitly specify each attribute value whose natural language needs to be overridden.
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Other values in a multi-valued 'name' attribute in a request or a response revert to the natural language of the operation attribute.
In a create request, the Printer object MUST accept and store with the Job object any natural language in the "attributes-natural- language" operation attribute, whether the Printer object supports that natural language or not. Furthermore, the Printer object MUST accept and store any 'nameWithLanguage' attribute value, whether the Printer object supports that natural language or not. These requirements are independent of the value of the "ipp-attribute- fidelity" operation attribute that the client MAY supply.
Example: If the client supplies the "attributes-natural-language" operation attribute with the value: 'en' indicating English, but the "printer-name" attribute is in German, the client MUST use the 'nameWithLanguage' attribute syntax as follows:
'de': Natural Language Override indicating German 'Farbdrucker': the Printer name in German
See the "Encoding and Transport" document [RFC2910] section 3.9 for the encoding of the two parts and Appendix A for a detailed example of the 'nameWithLanguage' attribute syntax.
For purposes of matching two 'name' attribute values for equality, such as in job validation (where a client-supplied value for attribute "xxx" is checked to see if the value is among the values of the Printer object's corresponding "xxx-supported" attribute), the following match rules apply:
1. 'keyword' values never match 'name' values.
2. 'name' (nameWithoutLanguage and nameWithLanguage) values match if (1) the name parts match and (2) the Associated Natural- Language parts (see section 3.1.4.1) match. The matching rules are:
a. the name parts match if the two names are identical character by character, except it is RECOMMENDED that case be ignored. For example: 'Ajax-letter-head-white' MUST match 'Ajax-letter-head-white' and SHOULD match 'ajax- letter-head-white' and 'AJAX-LETTER-HEAD-WHITE'.
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b. the Associated Natural-Language parts match if the shorter of the two meets the syntactic requirements of RFC 1766 [RFC1766] and matches byte for byte with the longer. For example, 'en' matches 'en', 'en-us' and 'en-gb', but matches neither 'fr' nor 'e'.
The 'keyword' attribute syntax is a sequence of characters, length: 1 to 255, containing only the US-ASCII [ASCII] encoded values for lowercase letters ("a" - "z"), digits ("0" - "9"), hyphen ("-"), dot ("."), and underscore ("_"). The first character MUST be a lowercase letter. Furthermore, keywords MUST be in U.S. English.
This syntax type is used for enumerating semantic identifiers of entities in the abstract protocol, i.e., entities identified in this document. Keywords are used as attribute names or values of attributes. Unlike 'text' and 'name' attribute values, 'keyword' values MUST NOT use the Natural Language Override mechanism, since they MUST always be US-ASCII and U.S. English.
Keywords are for use in the protocol. A user interface will likely provide a mapping between protocol keywords and displayable user- friendly words and phrases which are localized to the natural language of the user. While the keywords specified in this document MAY be displayed to users whose natural language is U.S. English, they MAY be mapped to other U.S. English words for U.S. English users, since the user interface is outside the scope of this document.
In the definition for each attribute of this syntax type, the full set of defined keyword values for that attribute are listed.
When a keyword is used to represent an attribute (its name), it MUST be unique within the full scope of all IPP objects and attributes. When a keyword is used to represent a value of an attribute, it MUST be unique just within the scope of that attribute. That is, the same keyword MUST NOT be used for two different values within the same attribute to mean two different semantic ideas. However, the same keyword MAY be used across two or more attributes, representing different semantic ideas for each attribute. Section 6.1 describes how the protocol can be extended with new keyword values. Examples of attribute name keywords:
"job-name" "attributes-charset"
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Note: This document uses "type1", "type2", and "type3" prefixes to the "keyword" basic syntax to indicate different levels of review for extensions (see section 6.1).
The 'enum' attribute syntax is an enumerated integer value that is in the range from 1 to 2**31 - 1 (MAX). Each value has an associated 'keyword' name. In the definition for each attribute of this syntax type, the full set of possible values for that attribute are listed. This syntax type is used for attributes for which there are enum values assigned by other standards, such as SNMP MIBs. A number of attribute enum values in this document are also used for corresponding attributes in other standards [RFC1759]. This syntax type is not used for attributes to which the administrator may assign values. Section 6.1 describes how the protocol can be extended with new enum values.
Enum values are for use in the protocol. A user interface will provide a mapping between protocol enum values and displayable user- friendly words and phrases which are localized to the natural language of the user. While the enum symbols specified in this document MAY be displayed to users whose natural language is U.S. English, they MAY be mapped to other U.S. English words for U.S. English users, since the user interface is outside the scope of this document.
Note: SNMP MIBs use '2' for 'unknown' which corresponds to the IPP "out-of-band" value 'unknown'. See the description of the "out-of- band" values at the beginning of Section 4.1. Therefore, attributes of type 'enum' start at '3'.
Note: This document uses "type1", "type2", and "type3" prefixes to the "enum" basic syntax to indicate different levels of review for extensions (see section 6.1).
The 'uri' attribute syntax is any valid Uniform Resource Identifier or URI [RFC2396]. Most often, URIs are simply Uniform Resource Locators or URLs. The maximum length of URIs used as values of IPP attributes is 1023 octets. Although most other IPP attribute syntax types allow for only lower-cased values, this attribute syntax type conforms to the case-sensitive and case-insensitive rules specified in [RFC2396]. See also [IPP-IIG] for a discussion of case in URIs.
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The 'uriScheme' attribute syntax is a sequence of characters representing a URI scheme according to RFC 2396 [RFC2396]. Though RFC 2396 requires that the values be case-insensitive, IPP requires all lower case values in IPP attributes to simplify comparing by IPP clients and Printer objects.
Standard values for this syntax type are the following keywords:
'ipp': for IPP schemed URIs (e.g., "ipp:...") 'http': for HTTP schemed URIs (e.g., "http:...") 'https': for use with HTTPS schemed URIs (e.g., "https:...") (not on IETF standards track) 'ftp': for FTP schemed URIs (e.g., "ftp:...") 'mailto': for SMTP schemed URIs (e.g., "mailto:...") 'file': for file schemed URIs (e.g., "file:...")
A Printer object MAY support any URI 'scheme' that has been registered with IANA [IANA-MT]. The maximum length of URI 'scheme' values used to represent IPP attribute values is 63 octets.
The 'charset' attribute syntax is a standard identifier for a charset. A charset is a coded character set and encoding scheme. Charsets are used for labeling certain document contents and 'text' and 'name' attribute values. The syntax and semantics of this attribute syntax are specified in RFC 2046 [RFC2046] and contained in the IANA character-set Registry [IANA-CS] according to the IANA procedures [RFC2278]. Though RFC 2046 requires that the values be case-insensitive US-ASCII [ASCII], IPP requires all lower case values in IPP attributes to simplify comparing by IPP clients and Printer objects. When a character-set in the IANA registry has more than one name (alias), the name labeled as "(preferred MIME name)", if present, MUST be used.
The maximum length of 'charset' values used to represent IPP attribute values is 63 octets.
Some examples are:
'utf-8': ISO 10646 Universal Multiple-Octet Coded Character Set (UCS) represented as the UTF-8 [RFC2279] transfer encoding scheme in which US-ASCII is a subset charset. 'us-ascii': 7-bit American Standard Code for Information Interchange (ASCII), ANSI X3.4-1986 [ASCII]. That standard
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defines US-ASCII, but RFC 2045 [RFC2045] eliminates most of the control characters from conformant usage in MIME and IPP. 'iso-8859-1': 8-bit One-Byte Coded Character Set, Latin Alphabet Nr 1 [ISO8859-1]. That standard defines a coded character set that is used by Latin languages in the Western Hemisphere and Western Europe. US-ASCII is a subset charset.
Some attribute descriptions MAY place additional requirements on charset values that may be used, such as REQUIRED values that MUST be supported or additional restrictions, such as requiring that the charset have US- ASCII as a subset charset.
The 'naturalLanguage' attribute syntax is a standard identifier for a natural language and optionally a country. The values for this syntax type are defined by RFC 1766 [RFC1766]. Though RFC 1766 requires that the values be case-insensitive US-ASCII [ASCII], IPP requires all lower case to simplify comparing by IPP clients and Printer objects. Examples include:
'en': for English 'en-us': for US English 'fr': for French 'de': for German
The maximum length of 'naturalLanguage' values used to represent IPP attribute values is 63 octets.
The 'mimeMediaType' attribute syntax is the Internet Media Type (sometimes called MIME type) as defined by RFC 2046 [RFC2046] and registered according to the procedures of RFC 2048 [RFC2048] for identifying a document format. The value MAY include a charset, or other, parameter, depending on the specification of the Media Type in the IANA Registry [IANA-MT]. Although most other IPP syntax types allow for only lower-cased values, this syntax type allows for mixed-case values which are case-insensitive.
Examples are: 'text/html': An HTML document 'text/plain': A plain text document in US-ASCII (RFC 2046 indicates that in the absence of the charset parameter MUST mean US-ASCII rather than simply unspecified) [RFC2046]. 'text/plain; charset=US-ASCII': A plain text document in US-ASCII [52, 56].
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'text/plain; charset=ISO-8859-1': A plain text document in ISO 8859-1 (Latin 1) [ISO8859-1]. 'text/plain; charset=utf-8': A plain text document in ISO 10646 represented as UTF-8 [RFC2279] 'application/postscript': A PostScript document [RFC2046] 'application/vnd.hp-PCL': A PCL document [IANA-MT] (charset escape sequence embedded in the document data) 'application/pdf': Portable Document Format - see IANA MIME Media Type registry 'application/octet-stream': Auto-sense - see section 4.1.9.1
The maximum length of a 'mimeMediaType' value to represent IPP attribute values is 255 octets.
4.1.9.1 Application/octet-stream -- Auto-Sensing the document format
One special type is 'application/octet-stream'. If the Printer object supports this value, the Printer object MUST be capable of auto-sensing the format of the document data using an implementation-dependent method that examines some number of octets of the document data, either as part of the create operation and/or at document processing time. During auto-sensing, a Printer may determine that the document-data has a format that the Printer doesn't recognize. If the Printer determines this problem before returning an operation response, it rejects the request and returns the 'client-error-document-format-not-supported' status code. If the Printer determines this problem after accepting the request and returning an operation response with one of the successful status codes, the Printer adds the 'unsupported-document-format' value to the job's "job-state-reasons" attribute.
If the Printer object's default value attribute "document-format- default" is set to 'application/octet-stream', the Printer object not only supports auto-sensing of the document format, but will depend on the result of applying its auto-sensing when the client does not supply the "document-format" attribute. If the client supplies a document format value, the Printer MUST rely on the supplied attribute, rather than trust its auto-sensing algorithm. To summarize:
1. If the client does not supply a document format value, the Printer MUST rely on its default value setting (which may be 'application/octet-stream' indicating an auto-sensing mechanism). 2. If the client supplies a value other than 'application/octet- stream', the client is supplying valid information about the format of the document data and the Printer object MUST trust the client supplied value more than the outcome of applying an
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automatic format detection mechanism. For example, the client may be requesting the printing of a PostScript file as a 'text/plain' document. The Printer object MUST print a text representation of the PostScript commands rather than interpret the stream of PostScript commands and print the result. 3. If the client supplies a value of 'application/octet-stream', the client is indicating that the Printer object MUST use its auto-sensing mechanism on the client supplied document data whether auto-sensing is the Printer object's default or not.
Note: Since the auto-sensing algorithm is probabilistic, if the client requests both auto-sensing ("document-format" set to 'application/octet-stream') and true fidelity ("ipp-attribute- fidelity" set to 'true'), the Printer object might not be able to guarantee exactly what the end user intended (the auto-sensing algorithm might mistake one document format for another), but it is able to guarantee that its auto-sensing mechanism be used.
When a Printer performs auto-sensing of a document in a submitted job, it is RECOMMENDED that the Printer indicate to the user that such auto-sensing has occurred and which document-format was auto- sensed by printing that information on the job's job-start-sheet.
The 'octetString' attribute syntax is a sequence of octets encoded in a maximum of 1023 octets which is indicated in sub-section headers using the notation: octetString(MAX). This syntax type is used for opaque data.
The 'integer' attribute syntax is an integer value that is in the range from -2**31 (MIN) to 2**31 - 1 (MAX). Each individual attribute may specify the range constraint explicitly in sub-section headers if the range is different from the full range of possible integer values. For example: job-priority (integer(1:100)) for the "job-priority" attribute. However, the enforcement of that additional constraint is up to the IPP objects, not the protocol.
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The 'rangeOfInteger' attribute syntax is an ordered pair of integers that defines an inclusive range of integer values. The first integer specifies the lower bound and the second specifies the upper bound. If a range constraint is specified in the header description for an attribute in this document whose attribute syntax is 'rangeOfInteger' (i.e., 'X:Y' indicating X as a minimum value and Y as a maximum value), then the constraint applies to both integers.
The 'dateTime' attribute syntax is a standard, fixed length, 11 octet representation of the "DateAndTime" syntax as defined in RFC 2579 [RFC2579]. RFC 2579 also identifies an 8 octet representation of a "DateAndTime" value, but IPP objects MUST use the 11 octet representation. A user interface will provide a mapping between protocol dateTime values and displayable user-friendly words or presentation values and phrases which are localized to the natural language and date format of the user, including time zone.
The 'resolution' attribute syntax specifies a two-dimensional resolution in the indicated units. It consists of 3 values: a cross feed direction resolution (positive integer value), a feed direction resolution (positive integer value), and a units value. The semantics of these three components are taken from the Printer MIB [RFC1759] suggested values. That is, the cross feed direction component resolution component is the same as the prtMarkerAddressabilityXFeedDir object in the Printer MIB, the feed direction component resolution component is the same as the prtMarkerAddressabilityFeedDir in the Printer MIB, and the units component is the same as the prtMarkerAddressabilityUnit object in the Printer MIB (namely, '3' indicates dots per inch and '4' indicates dots per centimeter). All three values MUST be present even if the first two values are the same. Example: '300', '600', '3' indicates a 300 dpi cross-feed direction resolution, a 600 dpi feed direction resolution, since a '3' indicates dots per inch (dpi).
The '1setOf X' attribute syntax is 1 or more values of attribute syntax type X. This syntax type is used for multi-valued attributes. The syntax type is called '1setOf' rather than just 'setOf' as a reminder that the set of values MUST NOT be empty (i.e., a set of
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size 0). Sets are normally unordered. However each attribute description of this type may specify that the values MUST be in a certain order for that attribute.
Job Template attributes describe job processing behavior. Support for Job Template attributes by a Printer object is OPTIONAL (see section 12.2.3 for a description of support for OPTIONAL attributes). Also, clients OPTIONALLY supply Job Template attributes in create requests.
Job Template attributes conform to the following rules. For each Job Template attribute called "xxx":
1. If the Printer object supports "xxx" then it MUST support both a "xxx-default" attribute (unless there is a "No" in the table below) and a "xxx-supported" attribute. If the Printer object doesn't support "xxx", then it MUST support neither an "xxx- default" attribute nor an "xxx-supported" attribute, and it MUST treat an attribute "xxx" supplied by a client as unsupported. An attribute "xxx" may be supported for some document formats and not supported for other document formats. For example, it is expected that a Printer object would only support "orientation-requested" for some document formats (such as 'text/plain' or 'text/html') but not others (such as 'application/postscript').
2. "xxx" is OPTIONALLY supplied by the client in a create request. If "xxx" is supplied, the client is indicating a desired job processing behavior for this Job. When "xxx" is not supplied, the client is indicating that the Printer object apply its default job processing behavior at job processing time if the document content does not contain an embedded instruction indicating an xxx-related behavior.
Since an administrator MAY change the default value attribute after a Job object has been submitted but before it has been processed, the default value used by the Printer object at job processing time may be different that the default value in effect at job submission time.
3. The "xxx-supported" attribute is a Printer object attribute that describes which job processing behaviors are supported by that Printer object. A client can query the Printer object to find out what xxx-related behaviors are supported by inspecting the returned values of the "xxx-supported" attribute.
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Note: The "xxx" in each "xxx-supported" attribute name is singular, even though an "xxx-supported" attribute usually has more than one value, such as "job-sheet-supported", unless the "xxx" Job Template attribute is plural, such as "finishings" or "sides". In such cases the "xxx-supported" attribute names are: "finishings- supported" and "sides-supported".
4. The "xxx-default" default value attribute describes what will be done at job processing time when no other job processing information is supplied by the client (either explicitly as an IPP attribute in the create request or implicitly as an embedded instruction within the document data).
If an application wishes to present an end user with a list of supported values from which to choose, the application SHOULD query the Printer object for its supported value attributes. The application SHOULD also query the default value attributes. If the application then limits selectable values to only those value that are supported, the application can guarantee that the values supplied by the client in the create request all fall within the set of supported values at the Printer. When querying the Printer, the client MAY enumerate each attribute by name in the Get-Printer- Attributes Request, or the client MAY just name the "job-template" group in order to get the complete set of supported attributes (both supported and default attributes).
The "finishings" attribute is an example of a Job Template attribute. It can take on a set of values such as 'staple', 'punch', and/or 'cover'. A client can query the Printer object for the "finishings- supported" attribute and the "finishings-default" attribute. The supported attribute contains a set of supported values. The default value attribute contains the finishing value(s) that will be used for a new Job if the client does not supply a "finishings" attribute in the create request and the document data does not contain any corresponding finishing instructions. If the client does supply the "finishings" attribute in the create request, the IPP object validates the value or values to make sure that they are a subset of the supported values identified in the Printer object's "finishings- supported" attribute. See section 3.1.7.
The table below summarizes the names and relationships for all Job Template attributes. The first column of the table (labeled "Job Attribute") shows the name and syntax for each Job Template attribute in the Job object. These are the attributes that can optionally be supplied by the client in a create request. The last two columns (labeled "Printer: Default Value Attribute" and "Printer: Supported Values Attribute") show the name and syntax for each Job Template attribute in the Printer object (the default value attribute and the
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supported values attribute). A "No" in the table means the Printer MUST NOT support the attribute (that is, the attribute is simply not applicable). For brevity in the table, the 'text' and 'name' entries do not show the maximum length for each attribute.
This attribute specifies a priority for scheduling the Job. A higher value specifies a higher priority. The value 1 indicates the lowest possible priority. The value 100 indicates the highest possible priority. Among those jobs that are ready to print, a Printer MUST print all jobs with a priority value of n before printing those with a priority value of n-1 for all n.
If the Printer object supports this attribute, it MUST always support the full range from 1 to 100. No administrative restrictions are permitted. This way an end-user can always make full use of the entire range with any Printer object. If privileged jobs are implemented outside IPP/1.1, they MUST have priorities higher than 100, rather than restricting the range available to end-users.
If the client does not supply this attribute and this attribute is supported by the Printer object, the Printer object MUST use the value of the Printer object's "job-priority-default" at job submission time (unlike most Job Template attributes that are used if necessary at job processing time).
The syntax for the "job-priority-supported" is also integer(1:100). This single integer value indicates the number of priority levels supported. The Printer object MUST take the value supplied by the client and map it to the closest integer in a sequence of n integers
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values that are evenly distributed over the range from 1 to 100 using the formula:
roundToNearestInt((100x+50)/n)
where n is the value of "job-priority-supported" and x ranges from 0 through n-1.
For example, if n=1 the sequence of values is 50; if n=2, the sequence of values is: 25 and 75; if n = 3, the sequence of values is: 17, 50 and 83; if n = 10, the sequence of values is: 5, 15, 25, 35, 45, 55, 65, 75, 85, and 95; if n = 100, the sequence of values is: 1, 2, 3, ... 100.
If the value of the Printer object's "job-priority-supported" is 10 and the client supplies values in the range 1 to 10, the Printer object maps them to 5, in the range 11 to 20, the Printer object maps them to 15, etc.
This attribute specifies the named time period during which the Job MUST become a candidate for printing.
Standard keyword values for named time periods are:
'no-hold': immediately, if there are not other reasons to hold the job 'indefinite': - the job is held indefinitely, until a client performs a Release-Job (section 3.3.6) 'day-time': during the day 'evening': evening 'night': night 'weekend': weekend 'second-shift': second-shift (after close of business) 'third-shift': third-shift (after midnight)
An administrator MUST associate allowable print times with a named time period (by means outside the scope of this IPP/1.1 document). An administrator is encouraged to pick names that suggest the type of time period. An administrator MAY define additional values using the 'name' or 'keyword' attribute syntax, depending on implementation.
If the value of this attribute specifies a time period that is in the future, the Printer SHOULD add the 'job-hold-until-specified' value to the job's "job-state-reasons" attribute, MUST move the job to the
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'pending-held' state, and MUST NOT schedule the job for printing until the specified time-period arrives.
When the specified time period arrives, the Printer MUST remove the 'job-hold-until-specified' value from the job's "job-state-reason" attribute, if present. If there are no other job state reasons that keep the job in the 'pending-held' state, the Printer MUST consider the job as a candidate for processing by moving the job to the 'pending' state.
If this job attribute value is the named value 'no-hold', or the specified time period has already started, the job MUST be a candidate for processing immediately.
If the client does not supply this attribute and this attribute is supported by the Printer object, the Printer object MUST use the value of the Printer object's "job-hold-until-default" at job submission time (unlike most Job Template attributes that are used if necessary at job processing time).
This attribute determines which job start/end sheet(s), if any, MUST be printed with a job.
Standard keyword values are:
'none': no job sheet is printed 'standard': one or more site specific standard job sheets are printed, e.g. a single start sheet or both start and end sheet is printed
An administrator MAY define additional values using the 'name' or 'keyword' attribute syntax, depending on implementation.
The effect of this attribute on jobs with multiple documents MAY be affected by the "multiple-document-handling" job attribute (section 4.2.4), depending on the job sheet semantics.
This attribute is relevant only if a job consists of two or more documents. This attribute MUST be supported with at least one value if the Printer supports multiple documents per job (see sections 3.2.4 and 3.3.1). The attribute controls finishing operations and the placement of one or more print-stream pages into impressions and onto media sheets. When the value of the "copies" attribute exceeds 1, it also controls the order in which the copies that result from
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processing the documents are produced. For the purposes of this explanations, if "a" represents an instance of document data, then the result of processing the data in document "a" is a sequence of media sheets represented by "a(*)".
Standard keyword values are:
'single-document': If a Job object has multiple documents, say, the document data is called a and b, then the result of processing all the document data (a and then b) MUST be treated as a single sequence of media sheets for finishing operations; that is, finishing would be performed on the concatenation of the sequences a(*),b(*). The Printer object MUST NOT force the data in each document instance to be formatted onto a new print-stream page, nor to start a new impression on a new media sheet. If more than one copy is made, the ordering of the sets of media sheets resulting from processing the document data MUST be a(*), b(*), a(*), b(*), start on a new media sheet. 'separate-documents-uncollated-copies': If a Job object has multiple documents, say, the document data is called a and b, then the result of processing the data in each document instance MUST be treated as a single sequence of media sheets for finishing operations; that is, the sets a(*) and b(*) would each be finished separately. The Printer object MUST force each copy of the result of processing the data in a single document to start on a new media sheet. If more than one copy is made, the ordering of the sets of media sheets resulting from processing the document data MUST be a(*), a(*), ..., b(*), b(*) ... . 'separate-documents-collated-copies': If a Job object has multiple documents, say, the document data is called a and b, then the result of processing the data in each document instance MUST be treated as a single sequence of media sheets for finishing operations; that is, the sets a(*) and b(*) would each be finished separately. The Printer object MUST force each copy of the result of processing the data in a single document to start on a new media sheet. If more than one copy is made, the ordering of the sets of media sheets resulting from processing the document data MUST be a(*), b(*), a(*), b(*), ... . 'single-document-new-sheet': Same as 'single-document', except that the Printer object MUST ensure that the first impression of each document instance in the job is placed on a new media sheet. This value allows multiple documents to be stapled together with a single staple where each document starts on a new sheet.
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The 'single-document' value is the same as 'separate-documents- collated-copies' with respect to ordering of print-stream pages, but not media sheet generation, since 'single-document' will put the first page of the next document on the back side of a sheet if an odd number of pages have been produced so far for the job, while 'separate-documents-collated- copies' always forces the next document or document copy on to a new sheet. In addition, if the "finishings" attribute specifies 'staple', then with 'single-document', documents a and b are stapled together as a single document with no regard to new sheets, with 'single-document-new-sheet', documents a and b are stapled together as a single document, but document b starts on a new sheet, but with 'separate-documents-uncollated-copies' and 'separate-documents-collated-copies', documents a and b are stapled separately.
Note: None of these values provide means to produce uncollated sheets within a document, i.e., where multiple copies of sheet n are produced before sheet n+1 of the same document.
The relationship of this attribute and the other attributes that control document processing is described in section 15.3.
This attribute specifies the number of copies to be printed.
On many devices the supported number of collated copies will be limited by the number of physical output bins on the device, and may be different from the number of uncollated copies which can be supported.
Note: The effect of this attribute on jobs with multiple documents is controlled by the "multiple-document-handling" job attribute (section 4.2.4) and the relationship of this attribute and the other attributes that control document processing is described in section 15.3.
This attribute identifies the finishing operations that the Printer uses for each copy of each printed document in the Job. For Jobs with multiple documents, the "multiple-document-handling" attribute determines what constitutes a "copy" for purposes of finishing.
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Standard enum values are:
Value Symbolic Name and Description
'3' 'none': Perform no finishing '4' 'staple': Bind the document(s) with one or more staples. The exact number and placement of the staples is site- defined. '5' 'punch': This value indicates that holes are required in the finished document. The exact number and placement of the holes is site-defined The punch specification MAY be satisfied (in a site- and implementation-specific manner) either by drilling/punching, or by substituting pre- drilled media. '6' 'cover': This value is specified when it is desired to select a non-printed (or pre-printed) cover for the document. This does not supplant the specification of a printed cover (on cover stock medium) by the document itself. '7' 'bind': This value indicates that a binding is to be applied to the document; the type and placement of the binding is site-defined. '8' 'saddle-stitch': Bind the document(s) with one or more staples (wire stitches) along the middle fold. The exact number and placement of the staples and the middle fold is implementation and/or site-defined. '9' 'edge-stitch': Bind the document(s) with one or more staples (wire stitches) along one edge. The exact number and placement of the staples is implementation and/or site- defined. '10'-'19' reserved for future generic finishing enum values.
The following values are more specific; they indicate a corner or an edge as if the document were a portrait document (see below):
'20' 'staple-top-left': Bind the document(s) with one or more staples in the top left corner. '21' 'staple-bottom-left': Bind the document(s) with one or more staples in the bottom left corner. '22' 'staple-top-right': Bind the document(s) with one or more staples in the top right corner. '23' 'staple-bottom-right': Bind the document(s) with one or more staples in the bottom right corner. '24' 'edge-stitch-left': Bind the document(s) with one or more staples (wire stitches) along the left edge. The exact number and placement of the staples is implementation and/or site-defined.
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'25' 'edge-stitch-top': Bind the document(s) with one or more staples (wire stitches) along the top edge. The exact number and placement of the staples is implementation and/or site-defined. '26' 'edge-stitch-right': Bind the document(s) with one or more staples (wire stitches) along the right edge. The exact number and placement of the staples is implementation and/or site-defined. '27' 'edge-stitch-bottom': Bind the document(s) with one or more staples (wire stitches) along the bottom edge. The exact number and placement of the staples is implementation and/or site-defined. '28' 'staple-dual-left': Bind the document(s) with two staples (wire stitches) along the left edge assuming a portrait document (see above). '29' 'staple-dual-top': Bind the document(s) with two staples (wire stitches) along the top edge assuming a portrait document (see above). '30' 'staple-dual-right': Bind the document(s) with two staples (wire stitches) along the right edge assuming a portrait document (see above). '31' 'staple-dual-bottom': Bind the document(s) with two staples (wire stitches) along the bottom edge assuming a portrait document (see above).
The 'staple-xxx' values are specified with respect to the document as if the document were a portrait document. If the document is actually a landscape or a reverse-landscape document, the client supplies the appropriate transformed value. For example, to position a staple in the upper left hand corner of a landscape document when held for reading, the client supplies the 'staple-bottom-left' value (since landscape is defined as a +90 degree rotation of the image with respect to the media from portrait, i.e., anti-clockwise). On the other hand, to position a staple in the upper left hand corner of a reverse-landscape document when held for reading, the client supplies the 'staple-top-right' value (since reverse-landscape is defined as a -90 degree rotation of the image with respect to the media from portrait, i.e., clockwise).
The angle (vertical, horizontal, angled) of each staple with respect to the document depends on the implementation which may in turn depend on the value of the attribute.
Note: The effect of this attribute on jobs with multiple documents is controlled by the "multiple-document-handling" job attribute (section 4.2.4) and the relationship of this attribute and the other attributes that control document processing is described in section 15.3.
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If the client supplies a value of 'none' along with any other combination of values, it is the same as if only that other combination of values had been supplied (that is the 'none' value has no effect).
This attribute identifies the range(s) of print-stream pages that the Printer object uses for each copy of each document which are to be printed. Nothing is printed for any pages identified that do not exist in the document(s). Ranges MUST be in ascending order, for example: 1-3, 5-7, 15-19 and MUST NOT overlap, so that a non-spooling Printer object can process the job in a single pass. If the ranges are not ascending or are overlapping, the IPP object MUST reject the request and return the 'client-error-bad-request' status code. The attribute is associated with print-stream pages not application- numbered pages (for example, the page numbers found in the headers and or footers for certain word processing applications).
For Jobs with multiple documents, the "multiple-document-handling" attribute determines what constitutes a "copy" for purposes of the specified page range(s). When "multiple-document-handling" is 'single-document', the Printer object MUST apply each supplied page range once to the concatenation of the print-stream pages. For example, if there are 8 documents of 10 pages each, the page-range '41:60' prints the pages in the 5th and 6th documents as a single document and none of the pages of the other documents are printed. When "multiple-document- handling" is 'separate-documents- uncollated-copies' or 'separate-documents-collated-copies', the Printer object MUST apply each supplied page range repeatedly to each document copy. For the same job, the page-range '1:3, 10:10' would print the first 3 pages and the 10th page of each of the 8 documents in the Job, as 8 separate documents.
In most cases, the exact pages to be printed will be generated by a device driver and this attribute would not be required. However, when printing an archived document which has already been formatted, the end user may elect to print just a subset of the pages contained in the document. In this case, if page-range = n.m is specified, the first page to be printed will be page n. All subsequent pages of the document will be printed through and including page m.
"page-ranges-supported" is a boolean value indicating whether or not the printer is capable of supporting the printing of page ranges. This capability may differ from one PDL to another. There is no "page-ranges-default" attribute. If the "page-ranges" attribute is not supplied by the client, all pages of the document will be printed.
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Note: The effect of this attribute on jobs with multiple documents is controlled by the "multiple-document-handling" job attribute (section 4.2.4) and the relationship of this attribute and the other attributes that control document processing is described in section 15.3.
This attribute specifies how print-stream pages are to be imposed upon the sides of an instance of a selected medium, i.e., an impression.
The standard keyword values are:
'one-sided': imposes each consecutive print-stream page upon the same side of consecutive media sheets. 'two-sided-long-edge': imposes each consecutive pair of print- stream pages upon front and back sides of consecutive media sheets, such that the orientation of each pair of print-stream pages on the medium would be correct for the reader as if for binding on the long edge. This imposition is sometimes called 'duplex' or 'head-to-head'. 'two-sided-short-edge': imposes each consecutive pair of print- stream pages upon front and back sides of consecutive media sheets, such that the orientation of each pair of print-stream pages on the medium would be correct for the reader as if for binding on the short edge. This imposition is sometimes called 'tumble' or 'head-to-toe'. 'two-sided-long-edge', 'two-sided-short-edge', 'tumble', and 'duplex' all work the same for portrait or landscape. However 'head-to-toe' is 'tumble' in portrait but 'duplex' in landscape. 'head-to-head' also switches between 'duplex' and 'tumble' when using portrait and landscape modes.
Note: The effect of this attribute on jobs with multiple documents is controlled by the "multiple-document-handling" job attribute (section 4.2.4) and the relationship of this attribute and the other attributes that control document processing is described in section 15.3.
This attribute specifies the number of print-stream pages to impose upon a single side of an instance of a selected medium. For example, if the value is:
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Value Description
'1' the Printer MUST place one print-stream page on a single side of an instance of the selected medium (MAY add some sort of translation, scaling, or rotation). '2' the Printer MUST place two print-stream pages on a single side of an instance of the selected medium (MAY add some sort of translation, scaling, or rotation). '4' the Printer MUST place four print-stream pages on a single side of an instance of the selected medium (MAY add some sort of translation, scaling, or rotation).
This attribute primarily controls the translation, scaling and rotation of print-stream pages.
Note: The effect of this attribute on jobs with multiple documents is controlled by the "multiple-document-handling" job attribute (section 4.2.4) and the relationship of this attribute and the other attributes that control document processing is described in section 15.3.
This attribute indicates the desired orientation for printed print- stream pages; it does not describe the orientation of the client- supplied print-stream pages.
For some document formats (such as 'application/postscript'), the desired orientation of the print-stream pages is specified within the document data. This information is generated by a device driver prior to the submission of the print job. Other document formats (such as 'text/plain') do not include the notion of desired orientation within the document data. In the latter case it is possible for the Printer object to bind the desired orientation to the document data after it has been submitted. It is expected that a Printer object would only support "orientations-requested" for some document formats (e.g., 'text/plain' or 'text/html') but not others (e.g., 'application/postscript'). This is no different than any other Job Template attribute since section 4.2, item 1, points out that a Printer object may support or not support any Job Template attribute based on the document format supplied by the client. However, a special mention is made here since it is very likely that a Printer object will support "orientation-requested" for only a subset of the supported document formats.
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Standard enum values are:
Value Symbolic Name and Description
'3' 'portrait': The content will be imaged across the short edge of the medium. '4' 'landscape': The content will be imaged across the long edge of the medium. Landscape is defined to be a rotation of the print-stream page to be imaged by +90 degrees with respect to the medium (i.e. anti-clockwise) from the portrait orientation. Note: The +90 direction was chosen because simple finishing on the long edge is the same edge whether portrait or landscape '5' 'reverse-landscape': The content will be imaged across the long edge of the medium. Reverse-landscape is defined to be a rotation of the print-stream page to be imaged by - 90 degrees with respect to the medium (i.e. clockwise) from the portrait orientation. Note: The 'reverse- landscape' value was added because some applications rotate landscape -90 degrees from portrait, rather than +90 degrees. '6' 'reverse-portrait': The content will be imaged across the short edge of the medium. Reverse-portrait is defined to be a rotation of the print-stream page to be imaged by 180 degrees with respect to the medium from the portrait orientation. Note: The 'reverse-portrait' value was added for use with the "finishings" attribute in cases where the opposite edge is desired for finishing a portrait document on simple finishing devices that have only one finishing position. Thus a 'text'/plain' portrait document can be stapled "on the right" by a simple finishing device as is common use with some middle eastern languages such as Hebrew.
Note: The effect of this attribute on jobs with multiple documents is controlled by the "multiple-document-handling" job attribute (section 4.2.4) and the relationship of this attribute and the other attributes that control document processing is described in section 15.3.
This attribute identifies the medium that the Printer uses for all impressions of the Job.
The values for "media" include medium-names, medium-sizes, input- trays and electronic forms so that one attribute specifies the media. If a Printer object supports a medium name as a value of this
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attribute, such a medium name implicitly selects an input-tray that contains the specified medium. If a Printer object supports a medium size as a value of this attribute, such a medium size implicitly selects a medium name that in turn implicitly selects an input-tray that contains the medium with the specified size. If a Printer object supports an input-tray as the value of this attribute, such an input-tray implicitly selects the medium that is in that input-tray at the time the job prints. This case includes manual-feed input- trays. If a Printer object supports an electronic form as the value of this attribute, such an electronic form implicitly selects a medium-name that in turn implicitly selects an input-tray that contains the medium specified by the electronic form. The electronic form also implicitly selects an image that the Printer MUST merge with the document data as its prints each page.
Standard keyword values are taken from ISO DPA [ISO10175], the Printer MIB [RFC1759], and ASME-Y14.1M [ASME-Y14.1M] and are listed in section 14. An administrator MAY define additional values using the 'name' or 'keyword' attribute syntax, depending on implementation.
There is also an additional Printer attribute named "media-ready" which differs from "media-supported" in that legal values only include the subset of "media-supported" values that are physically loaded and ready for printing with no operator intervention required. If an IPP object supports "media-supported", it NEED NOT support "media-ready".
The relationship of this attribute and the other attributes that control document processing is described in section 15.3.
This attribute specifies the print quality that the Printer uses for the Job.
The standard enum values are:
Value Symbolic Name and Description
'3' 'draft': lowest quality available on the printer '4' 'normal': normal or intermediate quality on the printer '5' 'high': highest quality available on the printer
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The attributes in this section form the attribute group called "job- description". The following table summarizes these attributes. The third column indicates whether the attribute is a REQUIRED attribute that MUST be supported by Printer objects. If it is not indicated as REQUIRED, then it is OPTIONAL. The maximum size in octets for 'text' and 'name' attributes is indicated in parenthesizes.
This REQUIRED attribute contains the URI for the job. The Printer object, on receipt of a new job, generates a URI which identifies the new Job. The Printer object returns the value of the "job-uri" attribute as part of the response to a create request. The precise format of a Job URI is implementation dependent. If the Printer object supports more than one URI and there is some relationship between the newly formed Job URI and the Printer object's URI, the Printer object uses the Printer URI supplied by the client in the create request. For example, if the create request comes in over a secure channel, the new Job URI MUST use the same secure channel. This can be guaranteed because the Printer object is responsible for generating the Job URI and the Printer object is aware of its security configuration and policy as well as the Printer URI used in the create request.
For a description of this attribute and its relationship to "job-id" and "job-printer-uri" attribute, see the discussion in section 2.4 on "Object Identity".
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This REQUIRED attribute contains the ID of the job. The Printer, on receipt of a new job, generates an ID which identifies the new Job on that Printer. The Printer returns the value of the "job-id" attribute as part of the response to a create request. The 0 value is not included to allow for compatibility with SNMP index values which also cannot be 0.
For a description of this attribute and its relationship to "job-uri" and "job-printer-uri" attribute, see the discussion in section 2.4 on "Object Identity".
This REQUIRED attribute identifies the Printer object that created this Job object. When a Printer object creates a Job object, it populates this attribute with the Printer object URI that was used in the create request. This attribute permits a client to identify the Printer object that created this Job object when only the Job object's URI is available to the client. The client queries the creating Printer object to determine which languages, charsets, operations, are supported for this Job.
For a description of this attribute and its relationship to "job-uri" and "job-id" attribute, see the discussion in section 2.4 on "Object Identity".
Similar to "printer-more-info", this attribute contains the URI referencing some resource with more information about this Job object, perhaps an HTML page containing information about the Job.
This REQUIRED attribute is the name of the job. It is a name that is more user friendly than the "job-uri" attribute value. It does not need to be unique between Jobs. The Job's "job-name" attribute is set to the value supplied by the client in the "job-name" operation attribute in the create request (see Section 3.2.1.1). If, however, the "job-name" operation attribute is not supplied by the client in the create request, the Printer object, on creation of the Job, MUST generate a name. The printer SHOULD generate the value of the Job's "job-name" attribute from the first of the following sources that produces a value: 1) the "document-name" operation attribute of the
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first (or only) document, 2) the "document-URI" attribute of the first (or only) document, or 3) any other piece of Job specific and/or Document Content information.
This REQUIRED attribute contains the name of the end user that submitted the print job. The Printer object sets this attribute to the most authenticated printable name that it can obtain from the authentication service over which the IPP operation was received. Only if such is not available, does the Printer object use the value supplied by the client in the "requesting-user-name" operation attribute of the create operation (see Sections 4.4.2, 4.4.3, and 8).
Note: The Printer object needs to keep an internal originating user id of some form, typically as a credential of a principal, with the Job object. Since such an internal attribute is implementation- dependent and not of interest to clients, it is not specified as a Job Description attribute. This originating user id is used for authorization checks (if any) on all subsequent operations.
This REQUIRED attribute identifies the current state of the job. Even though the IPP protocol defines seven values for job states (plus the out-of-band 'unknown' value - see Section 4.1), implementations only need to support those states which are appropriate for the particular implementation. In other words, a Printer supports only those job states implemented by the output device and available to the Printer object implementation.
Standard enum values are:
Values Symbolic Name and Description
'3' 'pending': The job is a candidate to start processing, but is not yet processing.
'4' 'pending-held': The job is not a candidate for processing for any number of reasons but will return to the 'pending' state as soon as the reasons are no longer present. The job's "job-state-reason" attribute MUST indicate why the job is no longer a candidate for processing.
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'5' 'processing': One or more of:
1. the job is using, or is attempting to use, one or more purely software processes that are analyzing, creating, or interpreting a PDL, etc., 2. the job is using, or is attempting to use, one or more hardware devices that are interpreting a PDL, making marks on a medium, and/or performing finishing, such as stapling, etc., 3. the Printer object has made the job ready for printing, but the output device is not yet printing it, either because the job hasn't reached the output device or because the job is queued in the output device or some other spooler, awaiting the output device to print it.
When the job is in the 'processing' state, the entire job state includes the detailed status represented in the Printer object's "printer-state", "printer-state- reasons", and "printer-state-message" attributes.
Implementations MAY, though they NEED NOT, include additional values in the job's "job-state-reasons" attribute to indicate the progress of the job, such as adding the 'job-printing' value to indicate when the output device is actually making marks on paper and/or the 'processing-to-stop-point' value to indicate that the IPP object is in the process of canceling or aborting the job. Most implementations won't bother with this nuance.
'6' 'processing-stopped': The job has stopped while processing for any number of reasons and will return to the 'processing' state as soon as the reasons are no longer present.
The job's "job-state-reason" attribute MAY indicate why the job has stopped processing. For example, if the output device is stopped, the 'printer-stopped' value MAY be included in the job's "job-state-reasons" attribute.
Note: When an output device is stopped, the device usually indicates its condition in human readable form locally at the device. A client can obtain more complete device status remotely by querying the Printer object's "printer-state", "printer-state-reasons" and "printer- state-message" attributes.
'7' 'canceled': The job has been canceled by a Cancel-Job operation and the Printer object has completed canceling
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the job and all job status attributes have reached their final values for the job. While the Printer object is canceling the job, the job remains in its current state, but the job's "job-state-reasons" attribute SHOULD contain the 'processing-to-stop-point' value and one of the 'canceled-by-user', 'canceled-by-operator', or 'canceled-at-device' value. When the job moves to the 'canceled' state, the 'processing-to-stop-point' value, if present, MUST be removed, but the 'canceled-by-xxx', if present, MUST remain.
'8' 'aborted': The job has been aborted by the system, usually while the job was in the 'processing' or 'processing- stopped' state and the Printer has completed aborting the job and all job status attributes have reached their final values for the job. While the Printer object is aborting the job, the job remains in its current state, but the job's "job-state-reasons" attribute SHOULD contain the 'processing-to-stop-point' and 'aborted-by- system' values. When the job moves to the 'aborted' state, the 'processing-to-stop-point' value, if present, MUST be removed, but the 'aborted-by-system' value, if present, MUST remain.
'9' 'completed': The job has completed successfully or with warnings or errors after processing and all of the job media sheets have been successfully stacked in the appropriate output bin(s) and all job status attributes have reached their final values for the job. The job's "job-state-reasons" attribute SHOULD contain one of: 'completed-successfully', 'completed-with-warnings', or 'completed-with-errors' values.
The final value for this attribute MUST be one of: 'completed', 'canceled', or 'aborted' before the Printer removes the job altogether. The length of time that jobs remain in the 'canceled', 'aborted', and 'completed' states depends on implementation. See section 4.3.7.2.
The following figure shows the normal job state transitions.
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Normally a job progresses from left to right. Other state transitions are unlikely, but are not forbidden. Not shown are the transitions to the 'canceled' state from the 'pending', 'pending- held', and 'processing-stopped' states.
Jobs reach one of the three terminal states: 'completed', 'canceled', or 'aborted', after the jobs have completed all activity, including stacking output media, after the jobs have completed all activity, and all job status attributes have reached their final values for the job.
As with all other IPP attributes, if the implementation cannot determine the correct value for this attribute, it SHOULD respond with the out-of-band value 'unknown' (see section 4.1) rather than try to guess at some possibly incorrect value and give the end user the wrong impression about the state of the Job object. For example, if the implementation is just a gateway into some printing system from which it can normally get status, but temporarily is unable, then the implementation should return the 'unknown' value. However, if the implementation is a gateway to a printing system that never provides detailed status about the print job, the implementation MAY set the IPP Job object's state to 'completed', provided that it also sets the 'queued-in-device' value in the job's "job-state-reasons" attribute (see section 4.3.8).
This section partitions the 7 job states into phases: Job Not Completed, Job Retention, Job History, and Job Removal. This section also explains the 'job-restartable' value of the "job-state-reasons" Job Description attribute for use with the Restart-Job operation.
Job Not Completed: When a job is in the 'pending', 'pending-held', 'processing', or 'processing-stopped' states, the job is not completed.
Job Retention: When a job enters one of the three terminal job states: 'completed', 'canceled', or 'aborted', the IPP Printer object MAY "retain" the job in a restartable condition for an implementation-defined time period. This time period MAY be zero seconds and MAY depend on the terminal job state. This phase is called Job Retention. While in the Job Retention phase, the job's document data is retained and a client may restart the job using the Restart-Job operation. If the IPP object supports the Restart-Job
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operation, then it SHOULD indicate that the job is restartable by adding the 'job-restartable' value to the job's "job-state-reasons" attribute (see Section 4.3.8) during the Job Retention phase.
Job History: After the Job Retention phase expires for a job, the Printer object deletes the document data for the job and the job becomes part of the Job History. The Printer object MAY also delete any number of the job attributes. Since the job is no longer restartable, the Printer object MUST remove the 'job-restartable' value from the job's "job-state-reasons" attribute, if present.
Job Removal: After the job has remained in the Job History for an implementation-defined time, such as when the number of jobs exceeds a fixed number or after a fixed time period (which MAY be zero seconds), the IPP Printer removes the job from the system.
Using the Get-Jobs operation and supplying the 'not-completed' value for the "which-jobs" operation attribute, a client is requesting jobs in the Job Not Completed phase. Using the Get-Jobs operation and supplying the 'completed' value for the "which-jobs" operation attribute, a client is requesting jobs in the Job Retention and Job History phases. Using the Get-Job-Attributes operation, a client is requesting a job in any phase except Job Removal. After Job Removal, the Get-Job-Attributes and Get-Jobs operations no longer are capable of returning any information about a job.
This REQUIRED attribute provides additional information about the job's current state, i.e., information that augments the value of the job's "job-state" attribute.
These values MAY be used with any job state or states for which the reason makes sense. Some of these value definitions indicate conformance requirements; the rest are OPTIONAL. Furthermore, when implemented, the Printer MUST return these values when the reason applies and MUST NOT return them when the reason no longer applies whether the value of the Job's "job-state" attribute changed or not. When the Job does not have any reasons for being in its current state, the value of the Job's "job-state-reasons" attribute MUST be 'none'.
Note: While values cannot be added to the 'job-state' attribute without impacting deployed clients that take actions upon receiving "job-state" values, it is the intent that additional "job-state- reasons" values can be defined and registered without impacting such deployed clients. In other words, the "job-state-reasons" attribute is intended to be extensible.
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The following standard keyword values are defined. For ease of understanding, the values are presented in the order in which the reasons are likely to occur (if implemented), starting with the 'job-incoming' value:
'none': There are no reasons for the job's current state. This state reason is semantically equivalent to "job-state-reasons" without any value and MUST be used when there is no other value, since the 1setOf attribute syntax requires at least one value. 'job-incoming': Either (1) the Printer has accepted the Create- Job operation and is expecting additional Send-Document and/or Send-URI operations, or (2) the Printer is retrieving/accepting document data as a result of a Print-Job, Print-URI, Send- Document or Send-URI operation. 'job-data-insufficient': The Create-Job operation has been accepted by the Printer, but the Printer is expecting additional document data before it can move the job into the 'processing' state. If a Printer starts processing before it has received all data, the Printer removes the 'job-data- insufficient' reason, but the 'job-incoming' remains. If a Printer starts processing after it has received all data, the Printer removes the 'job-data-insufficient' reason and the 'job-incoming' at the same time. 'document-access-error': After accepting a Print-URI or Send-URI request, the Printer could not access one or more documents passed by reference. This reason is intended to cover any file access problem, including file does not exist and access denied because of an access control problem. The Printer MAY also indicate the document access error using the "job-document- access-errors" Job Description attribute (see section 4.3.11). Whether the Printer aborts the job and moves the job to the 'aborted' job state or prints all documents that are accessible and moves the job to the 'completed' job state and adds the 'completed-with-errors' value in the job's "job-state-reasons" attribute depends on implementation and/or site policy. This value SHOULD be supported if the Print-URI or Send-URI operations are supported. 'submission-interrupted': The job was not completely submitted for some unforeseen reason, such as: (1) the Printer has crashed before the job was closed by the client, (2) the Printer or the document transfer method has crashed in some non-recoverable way before the document data was entirely transferred to the Printer, (3) the client crashed or failed to close the job before the time-out period. See section 4.4.31. 'job-outgoing': The Printer is transmitting the job to the output device.
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'job-hold-until-specified': The value of the job's "job-hold- until" attribute was specified with a time period that is still in the future. The job MUST NOT be a candidate for processing until this reason is removed and there are no other reasons to hold the job. This value SHOULD be supported if the "job- hold-until" Job Template attribute is supported. 'resources-are-not-ready': At least one of the resources needed by the job, such as media, fonts, resource objects, etc., is not ready on any of the physical printer's for which the job is a candidate. This condition MAY be detected when the job is accepted, or subsequently while the job is pending or processing, depending on implementation. The job may remain in its current state or be moved to the 'pending-held' state, depending on implementation and/or job scheduling policy. 'printer-stopped-partly': The value of the Printer's "printer- state-reasons" attribute contains the value 'stopped-partly'. 'printer-stopped': The value of the Printer's "printer-state" attribute is 'stopped'. 'job-interpreting': Job is in the 'processing' state, but more specifically, the Printer is interpreting the document data. 'job-queued': Job is in the 'processing' state, but more specifically, the Printer has queued the document data. 'job-transforming': Job is in the 'processing' state, but more specifically, the Printer is interpreting document data and producing another electronic representation. 'job-queued-for-marker': Job is in any of the 'pending-held', 'pending', or 'processing' states, but more specifically, the Printer has completed enough processing of the document to be able to start marking and the job is waiting for the marker. Systems that require human intervention to release jobs using the Release-Job operation, put the job into the 'pending-held' job state. Systems that automatically select a job to use the marker put the job into the 'pending' job state or keep the job in the 'processing' job state while waiting for the marker, depending on implementation. All implementations put the job into (or back into) the 'processing' state when marking does begin. 'job-printing': The output device is marking media. This value is useful for Printers which spend a great deal of time processing (1) when no marking is happening and then want to show that marking is now happening or (2) when the job is in the process of being canceled or aborted while the job remains in the 'processing' state, but the marking has not yet stopped so that impression or sheet counts are still increasing for the job.
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'job-canceled-by-user': The job was canceled by the owner of the job using the Cancel-Job request, i.e., by a user whose authenticated identity is the same as the value of the originating user that created the Job object, or by some other authorized end-user, such as a member of the job owner's security group. This value SHOULD be supported. 'job-canceled-by-operator': The job was canceled by the operator using the Cancel-Job request, i.e., by a user who has been authenticated as having operator privileges (whether local or remote). If the security policy is to allow anyone to cancel anyone's job, then this value may be used when the job is canceled by other than the owner of the job. For such a security policy, in effect, everyone is an operator as far as canceling jobs with IPP is concerned. This value SHOULD be supported if the implementation permits canceling by other than the owner of the job. 'job-canceled-at-device': The job was canceled by an unidentified local user, i.e., a user at a console at the device. This value SHOULD be supported if the implementation supports canceling jobs at the console. 'aborted-by-system': The job (1) is in the process of being aborted, (2) has been aborted by the system and placed in the 'aborted' state, or (3) has been aborted by the system and placed in the 'pending-held' state, so that a user or operator can manually try the job again. This value SHOULD be supported. 'unsupported-compression': The job was aborted by the system because the Printer determined while attempting to decompress the document-data's that the compression is actually not among those supported by the Printer. This value MUST be supported, since "compressions is a REQUIRED operation attribute. 'compression-error': The job was aborted by the system because the Printer encountered an error in the document-data while decompressing it. If the Printer posts this reason, the document-data has already passed any tests that would have led to the 'unsupported-compression' job-state-reason. 'unsupported-document-format': The job was aborted by the system because the document-data's document-format is not among those supported by the Printer. If the client specifies the document-format as 'application/octet-stream', the printer MAY abort the job and post this reason even though the format is a member of the "document-format-supported" printer attribute, but not among the auto-sensed document-formats. This value MUST be supported, since "document-format" is a REQUIRED operation attribute.
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'document-format-error': The job was aborted by the system because the Printer encountered an error in the document-data while processing it. If the Printer posts this reason, the document-data has already passed any tests that would have led to the 'unsupported-document-format' job-state-reason. 'processing-to-stop-point': The requester has issued a Cancel-Job operation or the Printer object has aborted the job, but is still performing some actions on the job until a specified stop point occurs or job termination/cleanup is completed.
If the implementation requires some measurable time to cancel the job in the 'processing' or 'processing-stopped' job states, the IPP object MUST use this value to indicate that the Printer object is still performing some actions on the job while the job remains in the 'processing' or 'processing-stopped' state. After all the job's job description attributes have stopped incrementing, the Printer object moves the job from the 'processing' state to the 'canceled' or 'aborted' job states.
'service-off-line': The Printer is off-line and accepting no jobs. All 'pending' jobs are put into the 'pending-held' state. This situation could be true if the service's or document transform's input is impaired or broken. 'job-completed-successfully': The job completed successfully. This value SHOULD be supported. 'job-completed-with-warnings': The job completed with warnings. This value SHOULD be supported if the implementation detects warnings. 'job-completed-with-errors': The job completed with errors (and possibly warnings too). This value SHOULD be supported if the implementation detects errors. 'job-restartable' - This job is retained (see section 4.3.7.2) and is currently able to be restarted using the Restart-Job operation (see section 3.3.7). If 'job-restartable' is a value of the job's 'job-state-reasons' attribute, then the IPP object MUST accept a Restart-Job operation for that job. This value SHOULD be supported if the Restart-Job operation is supported. 'queued-in-device': The job has been forwarded to a device or print system that is unable to send back status. The Printer sets the job's "job-state " attribute to 'completed' and adds the 'queued-in-device' value to the job's "job-state-reasons" attribute to indicate that the Printer has no additional information about the job and never will have any better information. See section 4.3.7.1.
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This attribute specifies information about the "job-state" and "job- state-reasons" attributes in human readable text. If the Printer object supports this attribute, the Printer object MUST be able to generate this message in any of the natural languages identified by the Printer's "generated-natural-language-supported" attribute (see the "attributes-natural-language" operation attribute specified in Section 3.1.4.1).
The value SHOULD NOT contain additional information not contained in the values of the "job-state" and "job-states-reasons" attributes, such as interpreter error information. Otherwise, application programs might attempt to parse the (localized text). For such additional information such as interpreter errors for application program consumption or specific document access errors, new attributes with keyword values, needs to be developed and registered.
This attribute specifies additional detailed and technical information about the job. The Printer NEED NOT localize the message(s), since they are intended for use by the system administrator or other experienced technical persons. Localization might obscure the technical meaning of such messages. Clients MUST NOT attempt to parse the value of this attribute. See "job- document-access-errors" (section 4.3.11) for additional errors that a program can process.
This attribute provides additional information about each document access error for this job encountered by the Printer after it returned a response to the Print-URI or Send-URI operation and subsequently attempted to access document(s) supplied in the Print- URI or Send-URI operation. For errors in the protocol that is identified by the URI scheme in the "document-uri" operation attribute, such as 'http:' or 'ftp:', the error code is returned in parentheses, followed by the URI. For example:
This attribute indicates the number of documents in the job, i.e., the number of Send-Document, Send-URI, Print-Job, or Print-URI operations that the Printer has accepted for this job, regardless of whether the document data has reached the Printer object or not.
Implementations supporting the OPTIONAL Create-Job/Send- Document/Send-URI operations SHOULD support this attribute so that clients can query the number of documents in each job.
This attribute identifies the output device to which the Printer object has assigned this job. If an output device implements an embedded Printer object, the Printer object NEED NOT set this attribute. If a print server implements a Printer object, the value MAY be empty (zero- length string) or not returned until the Printer object assigns an output device to the job. This attribute is particularly useful when a single Printer object supports multiple devices (so called "fan-out" - see section 2.1).
This section defines the Job Description attributes that indicate the time at which certain events occur for a job. If the job event has not yet occurred, then the IPP object MUST return the 'no-value' out-of-band value (see the beginning of Section 4.1). The "time-at- xxx(integer)" attributes represent time as an 'integer' representing the number of seconds since the device was powered up (informally called "time ticks"). The "date-time-at-xxx(dateTime)" attributes represent time as 'dateTime' representing date and time (including an offset from UTC).
In order to populate these attributes, the Printer object copies the value(s) of the following Printer Description attributes at the time the event occurs:
1. the value in the Printer's "printer-up-time" attribute for the "time-at-xxx(integer)" attributes
2. the value in the Printer's "printer-current-time" attribute for the "date-time-at-xxx(dateTime)" attributes.
If the Printer resets its "printer-up-time" attribute to 1 on power- up (see section 4.4.29) and has persistent jobs, then it MUST change all of jobs' "time-at-xxx(integer)" (time tick) job attributes whose events have occurred either to:
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1. 0 to indicate that the event happened before the most recent power up OR
2. the negative of the number of seconds before the most recent power-up that the event took place, though the negative number NEED NOT reflect the exact number of seconds.
If a client queries a "time-at-xxx(integer)" time tick Job attribute and finds the value to be 0 or negative, the client MUST assume that the event occurred in some life other than the Printer's current life.
Note: A Printer does not change the values of any "date-time-at- xxx(dateTime)" job attributes on power-up.
This REQUIRED attribute indicates the time at which the Job object first began processing after the create operation or the most recent Restart-Job operation. The out-of-band 'no-value' value is returned if the job has not yet been in the 'processing' state (see the beginning of Section 4.1).
This REQUIRED attribute indicates the time at which the Job object completed (or was canceled or aborted). The out-of-band 'no-value' value is returned if the job has not yet completed, been canceled, or aborted (see the beginning of Section 4.1).
This REQUIRED Job Description attribute indicates the amount of time (in seconds) that the Printer implementation has been up and running. This attribute is an alias for the "printer-up-time" Printer Description attribute (see Section 4.4.29).
A client MAY request this attribute in a Get-Job-Attributes or Get- Jobs request and use the value returned in combination with other requested Event Time Job Description Attributes in order to display time attributes to a user. The difference between this attribute and the 'integer' value of a "time-at-xxx" attribute is the number of
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seconds ago that the "time-at-xxx" event occurred. A client can compute the wall-clock time at which the "time-at-xxx" event occurred by subtracting this difference from the client's wall-clock time.
This attribute indicates the date and time at which the Job object first began processing after the create operation or the most recent Restart-Job operation.
This attribute indicates the number of jobs that are "ahead" of this job in the relative chronological order of expected time to complete (i.e., the current scheduled order). For efficiency, it is only necessary to calculate this value when an operation is performed that requests this attribute.
This attribute provides a message from an operator, system administrator or "intelligent" process to indicate to the end user the reasons for modification or other management action taken on a job.
This sub-section defines job attributes that describe the size of the job. These attributes are not intended to be counters; they are intended to be useful routing and scheduling information if known. For these attributes, the Printer object may try to compute the value if it is not supplied in the create request. Even if the client does supply a value for these three attributes in the create request, the Printer object MAY choose to change the value if the Printer object is able to compute a value which is more accurate than the client supplied value. The Printer object may be able to determine the correct value for these attributes either right at job submission time or at any later point in time.
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This attribute specifies the total size of the document(s) in K octets, i.e., in units of 1024 octets requested to be processed in the job. The value MUST be rounded up, so that a job between 1 and 1024 octets MUST be indicated as being 1, 1025 to 2048 MUST be 2, etc.
This value MUST NOT include the multiplicative factors contributed by the number of copies specified by the "copies" attribute, independent of whether the device can process multiple copies without making multiple passes over the job or document data and independent of whether the output is collated or not. Thus the value is independent of the implementation and indicates the size of the document(s) measured in K octets independent of the number of copies.
This value MUST also not include the multiplicative factor due to a copies instruction embedded in the document data. If the document data actually includes replications of the document data, this value will include such replication. In other words, this value is always the size of the source document data, rather than a measure of the hardcopy output to be produced.
This attribute specifies the total size in number of impressions of the document(s) being submitted (see the definition of impression in section 12.2.5).
As with "job-k-octets", this value MUST NOT include the multiplicative factors contributed by the number of copies specified by the "copies" attribute, independent of whether the device can process multiple copies without making multiple passes over the job or document data and independent of whether the output is collated or not. Thus the value is independent of the implementation and reflects the size of the document(s) measured in impressions independent of the number of copies.
As with "job-k-octets", this value MUST also not include the multiplicative factor due to a copies instruction embedded in the document data. If the document data actually includes replications of the document data, this value will include such replication. In other words, this value is always the number of impressions in the source document data, rather than a measure of the number of impressions to be produced by the job.
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This attribute specifies the total number of media sheets to be produced for this job.
Unlike the "job-k-octets" and the "job-impressions" attributes, this value MUST include the multiplicative factors contributed by the number of copies specified by the "copies" attribute and a 'number of copies' instruction embedded in the document data, if any. This difference allows the system administrator to control the lower and upper bounds of both (1) the size of the document(s) with "job-k- octets-supported" and "job-impressions-supported" and (2) the size of the job with "job-media-sheets-supported".