Network Working Group                                      M. Nottingham
Request for Comments: 4229                                      J. Mogul
Category: Informational                                          HP Labs
                                                           December 2005

Status of This Memo

   This memo provides information for the Internet community.  It does
   not specify an Internet standard of any kind.  Distribution of this
   memo is unlimited.

Copyright Notice

   Copyright (C) The Internet Society (2005).

Abstract

   This document defines the initial contents of a permanent IANA
   registry for HTTP header fields and a provisional repository for HTTP
   header fields, per RFC 3864.

Table of Contents

   1. Introduction ....................................................4
   2. Registration Templates ..........................................4
      2.1. Permanent HTTP Header Field Registrations ..................5
         2.1.1. Header field: A-IM ....................................7
         2.1.2. Header field: Accept ..................................8
         2.1.3. Header field: Accept-Additions ........................8
         2.1.4. Header field: Accept-Charset ..........................8
         2.1.5. Header field: Accept-Encoding .........................9
         2.1.6. Header field: Accept-Features .........................9
         2.1.7. Header field: Accept-Language .........................9
         2.1.8. Header field: Accept-Ranges ..........................10
         2.1.9. Header field: Age ....................................10
         2.1.10. Header field: Allow .................................10
         2.1.11. Header field: Alternates ............................10
         2.1.12. Header field: Authentication-Info ...................11
         2.1.13. Header field: Authorization .........................11
         2.1.14. Header field: C-Ext .................................11
         2.1.15. Header field: C-Man .................................12
         2.1.16. Header field: C-Opt .................................12
         2.1.17. Header field: C-PEP .................................12
         2.1.18. Header field: C-PEP-Info ............................13
         2.1.19. Header field: Cache-Control .........................13
         2.1.20. Header field: Connection ............................13



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RFC 4229                   HTTP Header Fields              December 2005


         2.1.21. Header field: Content-Base ..........................14
         2.1.22. Header field: Content-Disposition ...................14
         2.1.23. Header field: Content-Encoding ......................14
         2.1.24. Header field: Content-ID ............................14
         2.1.25. Header field: Content-Language ......................15
         2.1.26. Header field: Content-Length ........................15
         2.1.27. Header field: Content-Location ......................15
         2.1.28. Header field: Content-MD5 ...........................16
         2.1.29. Header field: Content-Range .........................16
         2.1.30. Header field: Content-Script-Type ...................16
         2.1.31. Header field: Content-Style-Type ....................17
         2.1.32. Header field: Content-Type ..........................17
         2.1.33. Header field: Content-Version .......................17
         2.1.34. Header field: Cookie ................................17
         2.1.35. Header field: Cookie2 ...............................18
         2.1.36. Header field: DAV ...................................18
         2.1.37. Header field: Date ..................................18
         2.1.38. Header field: Default-Style .........................19
         2.1.39. Header field: Delta-Base ............................19
         2.1.40. Header field: Depth .................................19
         2.1.41. Header field: Derived-From ..........................19
         2.1.42. Header field: Destination ...........................20
         2.1.43. Header field: Differential-ID .......................20
         2.1.44. Header field: Digest ................................20
         2.1.45. Header field: ETag ..................................21
         2.1.46. Header field: Expect ................................21
         2.1.47. Header field: Expires ...............................21
         2.1.48. Header field: Ext ...................................22
         2.1.49. Header field: From ..................................22
         2.1.50. Header field: GetProfile ............................22
         2.1.51. Header field: Host ..................................23
         2.1.52. Header field: IM ....................................23
         2.1.53. Header field: If ....................................23
         2.1.54. Header field: If-Match ..............................23
         2.1.55. Header field: If-Modified-Since .....................24
         2.1.56. Header field: If-None-Match .........................24
         2.1.57. Header field: If-Range ..............................24
         2.1.58. Header field: If-Unmodified-Since ...................25
         2.1.59. Header field: Keep-Alive ............................25
         2.1.60. Header field: Label .................................25
         2.1.61. Header field: Last-Modified .........................25
         2.1.62. Header field: Link ..................................26
         2.1.63. Header field: Location ..............................26
         2.1.64. Header field: Lock-Token ............................26
         2.1.65. Header field: MIME-Version ..........................27
         2.1.66. Header field: Man ...................................27
         2.1.67. Header field: Max-Forwards ..........................27
         2.1.68. Header field: Meter .................................27



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RFC 4229                   HTTP Header Fields              December 2005


         2.1.69. Header field: Negotiate .............................28
         2.1.70. Header field: Opt ...................................28
         2.1.71. Header field: Ordering-Type .........................28
         2.1.72. Header field: Overwrite .............................29
         2.1.73. Header field: P3P ...................................29
         2.1.74. Header field: PEP ...................................29
         2.1.75. Header field: PICS-Label ............................30
         2.1.76. Header field: Pep-Info ..............................30
         2.1.77. Header field: Position ..............................30
         2.1.78. Header field: Pragma ................................31
         2.1.79. Header field: ProfileObject .........................31
         2.1.80. Header field: Protocol ..............................31
         2.1.81. Header field: Protocol-Info .........................32
         2.1.82. Header field: Protocol-Query ........................32
         2.1.83. Header field: Protocol-Request ......................32
         2.1.84. Header field: Proxy-Authenticate ....................32
         2.1.85. Header field: Proxy-Authentication-Info .............33
         2.1.86. Header field: Proxy-Authorization ...................33
         2.1.87. Header field: Proxy-Features ........................33
         2.1.88. Header field: Proxy-Instruction .....................34
         2.1.89. Header field: Public ................................34
         2.1.90. Header field: Range .................................34
         2.1.91. Header field: Referer ...............................34
         2.1.92. Header field: Retry-After ...........................35
         2.1.93. Header field: Safe ..................................35
         2.1.94. Header field: Security-Scheme .......................35
         2.1.95. Header field: Server ................................36
         2.1.96. Header field: Set-Cookie ............................36
         2.1.97. Header field: Set-Cookie2 ...........................36
         2.1.98. Header field: SetProfile ............................36
         2.1.99. Header field: SoapAction ............................37
         2.1.100. Header field: Status-URI ...........................37
         2.1.101. Header field: Surrogate-Capability .................38
         2.1.102. Header field: Surrogate-Control ....................38
         2.1.103. Header field: TCN ..................................38
         2.1.104. Header field: TE ...................................39
         2.1.105. Header field: Timeout ..............................39
         2.1.106. Header field: Trailer ..............................39
         2.1.107. Header field: Transfer-Encoding ....................39
         2.1.108. Header field: URI ..................................40
         2.1.109. Header field: Upgrade ..............................40
         2.1.110. Header field: User-Agent ...........................40
         2.1.111. Header field: Variant-Vary .........................41
         2.1.112. Header field: Vary .................................41
         2.1.113. Header field: Via ..................................41
         2.1.114. Header field: WWW-Authenticate .....................41
         2.1.115. Header field: Want-Digest ..........................42
         2.1.116. Header field: Warning ..............................42



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RFC 4229                   HTTP Header Fields              December 2005


      2.2. Provisional HTTP Header Field Submissions .................43
         2.2.1. Header field: Compliance .............................43
         2.2.2. Header field: Content-Transfer-Encoding ..............43
         2.2.3. Header field: Cost ...................................44
         2.2.4. Header field: Message-ID .............................44
         2.2.5. Header field: Non-Compliance .........................44
         2.2.6. Header field: Optional ...............................44
         2.2.7. Header field: Resolution-Hint ........................45
         2.2.8. Header field: Resolver-Location ......................45
         2.2.9. Header field: SubOK ..................................46
         2.2.10. Header field: Subst .................................46
         2.2.11. Header field: Title .................................46
         2.2.12. Header field: UA-Color ..............................46
         2.2.13. Header field: UA-Media ..............................47
         2.2.14. Header field: UA-Pixels .............................47
         2.2.15. Header field: UA-Resolution .........................48
         2.2.16. Header field: UA-Windowpixels .......................48
         2.2.17. Header field: Version ...............................48
   3. IANA Considerations ............................................49
   4. Security Considerations ........................................49
   5. Acknowledgements ...............................................49
   6. Informative References .........................................49

1.  Introduction

   HTTP/1.0 [3] and HTTP/1.1 [11] define protocol constructs
   (respectively, the HTTP-header and message-header BNF rules) that are
   used as message headers.  These specifications also define a number
   of HTTP headers themselves, and they provide for extension through
   the use of new field-names.

   This document defines the initial contents of an IANA registry that
   catalogs permanent HTTP header field-names, and of an IANA repository
   that catalogs provisional HTTP header field-names.  Both are operated
   according to Registration Procedures for Message Header Fields [1].

   Note that neither tracks the syntax or semantics of field-values.
   Also, while some HTTP headers have different semantics depending on
   their context (e.g., Cache-Control in requests and responses), both
   registries consider the HTTP header field-name name space singular.

   Also, some contact details listed may no longer be correct.

2.  Registration Templates

   Header field entries are summarized in tabular form for convenience
   of reference and presented in full in the following sections.




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RFC 4229                   HTTP Header Fields              December 2005

2.1.  Permanent HTTP Header Field Registrations

   Header name             Protocol
   -----------             --------
   A-IM                      http
   Accept                    http
   Accept-Additions          http
   Accept-Charset            http
   Accept-Encoding           http
   Accept-Features           http
   Accept-Language           http
   Accept-Ranges             http
   Age                       http
   Allow                     http
   Alternates                http
   Authentication-Info       http
   Authorization             http
   C-Ext                     http
   C-Man                     http
   C-Opt                     http
   C-PEP                     http
   C-PEP-Info                http
   Cache-Control             http
   Connection                http
   Content-Base              http
   Content-Disposition       http
   Content-Encoding          http
   Content-ID                http
   Content-Language          http
   Content-Length            http
   Content-Location          http
   Content-MD5               http
   Content-Range             http
   Content-Script-Type       http
   Content-Style-Type        http
   Content-Type              http
   Content-Version           http
   Cookie                    http
   Cookie2                   http
   DAV                       http
   Date                      http
   Default-Style             http
   Delta-Base                http
   Depth                     http
   Derived-From              http
   Destination               http
   Differential-ID           http
   Digest                    http



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RFC 4229                   HTTP Header Fields              December 2005


   ETag                      http
   Expect                    http
   Expires                   http
   Ext                       http
   From                      http
   GetProfile                http
   Host                      http
   IM                        http
   If                        http
   If-Match                  http
   If-Modified-Since         http
   If-None-Match             http
   If-Range                  http
   If-Unmodified-Since       http
   Keep-Alive                http
   Label                     http
   Last-Modified             http
   Link                      http
   Location                  http
   Lock-Token                http
   MIME-Version              http
   Man                       http
   Max-Forwards              http
   Meter                     http
   Negotiate                 http
   Opt                       http
   Ordering-Type             http
   Overwrite                 http
   P3P                       http
   PEP                       http
   PICS-Label                http
   Pep-Info                  http
   Position                  http
   Pragma                    http
   ProfileObject             http
   Protocol                  http
   Protocol-Info             http
   Protocol-Query            http
   Protocol-Request          http
   Proxy-Authenticate        http
   Proxy-Authentication-Info http
   Proxy-Authorization       http
   Proxy-Features            http
   Proxy-Instruction         http
   Public                    http
   Range                     http
   Referer                   http
   Retry-After               http



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RFC 4229                   HTTP Header Fields              December 2005


   Safe                      http
   Security-Scheme           http
   Server                    http
   Set-Cookie                http
   Set-Cookie2               http
   SetProfile                http
   SoapAction                http
   Status-URI                http
   Surrogate-Capability      http
   Surrogate-Control         http
   TCN                       http
   TE                        http
   Timeout                   http
   Trailer                   http
   Transfer-Encoding         http
   URI                       http
   Upgrade                   http
   User-Agent                http
   Variant-Vary              http
   Vary                      http
   Via                       http
   WWW-Authenticate          http
   Want-Digest               http
   Warning                   http

2.1.1.  Header field: A-IM

   Applicable protocol:     http [11]

   Status: standard

   Author/change controller:
      IETF  (iesg@ietf.org)
      Internet Engineering Task Force

   Specification document(s):
      RFC3229 [16]














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RFC 4229                   HTTP Header Fields              December 2005

2.1.2.  Header field: Accept

   Applicable protocol: http [11]

   Status: standard

   Author/change controller:
      IETF  (iesg@ietf.org)
      Internet Engineering Task Force

   Specification document(s):
      RFC2616 [11]

2.1.3.  Header field: Accept-Additions

   Applicable protocol: http [11]

   Status: informational

   Author/change controller:
      IETF  (iesg@ietf.org)
      Internet Engineering Task Force

   Specification document(s):
      RFC2324 [9]

   Related information: spoof

2.1.4.  Header field: Accept-Charset

   Applicable protocol: http [11]

   Status: standard

   Author/change controller:
      IETF  (iesg@ietf.org)
      Internet Engineering Task Force

   Specification document(s):
      RFC2616 [11]











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RFC 4229                   HTTP Header Fields              December 2005

2.1.5.  Header field: Accept-Encoding

   Applicable protocol: http [11]

   Status: standard

   Author/change controller:
      IETF  (iesg@ietf.org)
      Internet Engineering Task Force

   Specification document(s):
      RFC2616 [11]

2.1.6.  Header field: Accept-Features

   Applicable protocol: http [11]

   Status: experimental

   Author/change controller:
      Andrew H. Mutz  (mutz@hpl.hp.com)
      Koen Holtman  (koen@win.tue.nl)

   Specification document(s):
      RFC2295 [7]

2.1.7.  Header field: Accept-Language

   Applicable protocol: http [11]

   Status: standard

   Author/change controller:
      IETF  (iesg@ietf.org)
      Internet Engineering Task Force

   Specification document(s):
      RFC2616 [11]













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RFC 4229                   HTTP Header Fields              December 2005

2.1.8.  Header field: Accept-Ranges

   Applicable protocol: http [11]

   Status: standard

   Author/change controller:
      IETF  (iesg@ietf.org)
      Internet Engineering Task Force

   Specification document(s):
      RFC2616 [11]

2.1.9.  Header field: Age

   Applicable protocol: http [11]

   Status: standard

   Author/change controller:
      IETF  (iesg@ietf.org)
      Internet Engineering Task Force

   Specification document(s):
      RFC2616 [11]

2.1.10.  Header field: Allow

   Applicable protocol: http [11]

   Status: standard

   Author/change controller:
      IETF  (iesg@ietf.org)
      Internet Engineering Task Force

   Specification document(s):
      RFC2616 [11]

2.1.11.  Header field: Alternates

   Applicable protocol: http [11]

   Status: experimental







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RFC 4229                   HTTP Header Fields              December 2005


   Author/change controller:
      Andrew H. Mutz  (mutz@hpl.hp.com)
      Koen Holtman  (koen@win.tue.nl)

   Specification document(s):
      RFC2295 [7]

2.1.12.  Header field: Authentication-Info

   Applicable protocol: http [11]

   Status: standard

   Author/change controller:
      IETF  (iesg@ietf.org)
      Internet Engineering Task Force

   Specification document(s):
      RFC2617 [12]

2.1.13.  Header field: Authorization

   Applicable protocol: http [11]

   Status: standard

   Author/change controller:
      IETF  (iesg@ietf.org)
      Internet Engineering Task Force

   Specification document(s):
      RFC2616 [11]

2.1.14.  Header field: C-Ext

   Applicable protocol: http [11]

   Status: experimental

   Author/change controller:
      Henrik Frystyk Nielsen  (frystyk@microsoft.com)
      Paul J. Leach  (paulle@microsoft.com)
      Scott Lawrence  (lawrence@agranat.com)

   Specification document(s):
      RFC2774 [14]





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RFC 4229                   HTTP Header Fields              December 2005

2.1.15.  Header field: C-Man

   Applicable protocol: http [11]

   Status: experimental

   Author/change controller:
      Henrik Frystyk Nielsen  (frystyk@microsoft.com)
      Paul J. Leach  (paulle@microsoft.com)
      Scott Lawrence  (lawrence@agranat.com)

   Specification document(s):
      RFC2774 [14]

2.1.16.  Header field: C-Opt

   Applicable protocol: http [11]

   Status: experimental

   Author/change controller:
      Henrik Frystyk Nielsen  (frystyk@microsoft.com)
      Paul J. Leach  (paulle@microsoft.com)
      Scott Lawrence  (lawrence@agranat.com)

   Specification document(s):
      RFC2774 [14]

2.1.17.  Header field: C-PEP

   Applicable protocol: http [11]

   Status: deprecated

   Author/change controller:
      Henrik Frystyk Nielsen  (frystyk@w3.org)
      World Wide Web Consortium, MIT Laboratory for Computer Science
      Dan Connolly  (connolly@w3.org)
      World Wide Web Consortium, MIT Laboratory for Computer Science
      Rohit Khare  (khare@w3.org)
      World Wide Web Consortium, MIT Laboratory for Computer Science
      Eric Prud'hommeaux  (eric@w3.org)
      World Wide Web Consortium, MIT Laboratory for Computer Science

   Specification document(s):
      PEP [29]





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RFC 4229                   HTTP Header Fields              December 2005

2.1.18.  Header field: C-PEP-Info

   Applicable protocol: http [11]

   Status: deprecated

   Author/change controller:
      Henrik Frystyk Nielsen  (frystyk@w3.org)
      World Wide Web Consortium, MIT Laboratory for Computer Science
      Dan Connolly  (connolly@w3.org)
      World Wide Web Consortium, MIT Laboratory for Computer Science
      Rohit Khare  (khare@w3.org)
      World Wide Web Consortium, MIT Laboratory for Computer Science
      Eric Prud'hommeaux  (eric@w3.org)
      World Wide Web Consortium, MIT Laboratory for Computer Science

      Specification document(s):
         PEP [29]

2.1.19.  Header field: Cache-Control

   Applicable protocol: http [11]

   Status: standard

   Author/change controller:
      IETF  (iesg@ietf.org)
      Internet Engineering Task Force

   Specification document(s):
      RFC2616 [11]

2.1.20.  Header field: Connection

   Applicable protocol: http [11]

   Status: standard

   Author/change controller:
      IETF  (iesg@ietf.org)
      Internet Engineering Task Force

   Specification document(s):
      RFC2616 [11]







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RFC 4229                   HTTP Header Fields              December 2005

2.1.21.  Header field: Content-Base

   Applicable protocol: http [11]

   Status: standard

   Author/change controller:
      IETF  (iesg@ietf.org)
      Internet Engineering Task Force

   Specification document(s):
      RFC2068 [4]

2.1.22.  Header field: Content-Disposition

   Applicable protocol: http [11]

   Status: standard

   Author/change controller:
      IETF  (iesg@ietf.org)
      Internet Engineering Task Force

   Specification document(s):
      RFC2616 [11]

2.1.23.  Header field: Content-Encoding

   Applicable protocol: http [11]

   Status: standard

   Author/change controller:
      IETF  (iesg@ietf.org)
      Internet Engineering Task Force

   Specification document(s):
      RFC2616 [11]

2.1.24.  Header field: Content-ID

   Applicable protocol: http [11]

   Status: informational







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RFC 4229                   HTTP Header Fields              December 2005


   Author/change controller:
      Arthur van Hoff  (avh@marimba.com)
      Marimba Inc.
      John Giannandrea  (jg@netscape.com)
      Netscape Inc.
      Mark Hapner  (mark.hapner@sun.com)
      Sun Microsystems Inc.
      Steve Carter  (srcarter@novell.com)
      Novell Inc.
      Milo Medin  (medin@home.net)
      At Home Corp

   Specification document(s):
      DRP [20]

2.1.25.  Header field: Content-Language

   Applicable protocol: http [11]

   Status: standard

   Author/change controller:
      IETF  (iesg@ietf.org)
      Internet Engineering Task Force

   Specification document(s):
      RFC2616 [11]

2.1.26.  Header field: Content-Length

   Applicable protocol: http [11]

   Status: standard

   Author/change controller:
      IETF  (iesg@ietf.org)
      Internet Engineering Task Force

   Specification document(s):
      RFC2616 [11]

2.1.27.  Header field: Content-Location

   Applicable protocol: http [11]

   Status: standard





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   Author/change controller:
      IETF  (iesg@ietf.org)
      Internet Engineering Task Force

   Specification document(s):
      RFC2616 [11]

2.1.28.  Header field: Content-MD5

   Applicable protocol: http [11]

   Status: standard

   Author/change controller:
      IETF  (iesg@ietf.org)
      Internet Engineering Task Force

   Specification document(s):
      RFC2616 [11]

2.1.29.  Header field: Content-Range

   Applicable protocol: http [11]

   Status: standard

   Author/change controller:
      IETF  (iesg@ietf.org)
      Internet Engineering Task Force

   Specification document(s):
      RFC2616 [11]

2.1.30.  Header field: Content-Script-Type

   Applicable protocol: http [11]

   Status: standard

   Author/change controller:
      W3C  (web-human@w3.org)
      World Wide Web Consortium

   Specification document(s):
      HTML 4 [21]






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RFC 4229                   HTTP Header Fields              December 2005

2.1.31.  Header field: Content-Style-Type

   Applicable protocol: http [11]

   Status: standard

   Author/change controller:
      W3C  (web-human@w3.org)
      World Wide Web Consortium

   Specification document(s):
      HTML 4 [21]

2.1.32.  Header field: Content-Type

   Applicable protocol: http [11]

   Status: standard

   Author/change controller:
      IETF  (iesg@ietf.org)
      Internet Engineering Task Force

   Specification document(s):
      RFC2616 [11]

2.1.33.  Header field: Content-Version

   Applicable protocol: http [11]

   Status: standard

   Author/change controller:
      IETF  (iesg@ietf.org)
      Internet Engineering Task Force

   Specification document(s):
      RFC2068 [4]

2.1.34.  Header field: Cookie

   Applicable protocol: http [11]

   Status: standard







Nottingham & Mogul           Informational                     [Page 17]

RFC 4229                   HTTP Header Fields              December 2005


   Author/change controller:
      IETF  (iesg@ietf.org)
      Internet Engineering Task Force

   Specification document(s):
      RFC2965 [15]

2.1.35.  Header field: Cookie2

   Applicable protocol: http [11]

   Status: standard

   Author/change controller:
      IETF  (iesg@ietf.org)
      Internet Engineering Task Force

   Specification document(s):
      RFC2965 [15]

2.1.36.  Header field: DAV

   Applicable protocol: http [11]

   Status: standard

   Author/change controller:
      IETF  (iesg@ietf.org)
      Internet Engineering Task Force

   Specification document(s):
      RFC2518 [10]

2.1.37.  Header field: Date

   Applicable protocol: http [11]

   Status: standard

   Author/change controller:
      IETF  (iesg@ietf.org)
      Internet Engineering Task Force

   Specification document(s):
      RFC2616 [11]






Nottingham & Mogul           Informational                     [Page 18]

RFC 4229                   HTTP Header Fields              December 2005

2.1.38.  Header field: Default-Style

   Applicable protocol: http [11]

   Status: standard

   Author/change controller:
      W3C  (web-human@w3.org)
      World Wide Web Consortium

   Specification document(s):
      HTML 4 [21]

2.1.39.  Header field: Delta-Base

   Applicable protocol: http [11]

   Status: standard

   Author/change controller:
      IETF  (iesg@ietf.org)
      Internet Engineering Task Force

   Specification document(s):
      RFC3229 [16]

2.1.40.  Header field: Depth

   Applicable protocol: http [11]

   Status: standard

   Author/change controller:
      IETF  (iesg@ietf.org)
      Internet Engineering Task Force

   Specification document(s):
      RFC2518 [10]

2.1.41.  Header field: Derived-From

   Applicable protocol: http [11]

   Status: standard







Nottingham & Mogul           Informational                     [Page 19]

RFC 4229                   HTTP Header Fields              December 2005


   Author/change controller:
      IETF  (iesg@ietf.org)
      Internet Engineering Task Force

   Specification document(s):
      RFC2068 [4]

2.1.42.  Header field: Destination

   Applicable protocol: http [11]

   Status: standard

   Author/change controller:
      IETF  (iesg@ietf.org)
      Internet Engineering Task Force

   Specification document(s):
      RFC2518 [10]

2.1.43.  Header field: Differential-ID

   Applicable protocol: http [11]

   Status: informational

   Author/change controller:
      Arthur van Hoff  (avh@marimba.com)
      Marimba Inc.
      John Giannandrea  (jg@netscape.com)
      Netscape Inc.
      Mark Hapner  (mark.hapner@sun.com)
      Sun Microsystems Inc.
      Steve Carter  (srcarter@novell.com)
      Novell Inc.
      Milo Medin  (medin@home.net)
      At Home Corp

   Specification document(s):
      DRP [20]

2.1.44.  Header field: Digest

   Applicable protocol: http [11]

   Status: standard





Nottingham & Mogul           Informational                     [Page 20]

RFC 4229                   HTTP Header Fields              December 2005


   Author/change controller:
      IETF  (iesg@ietf.org)
      Internet Engineering Task Force

   Specification document(s):
      RFC3230 [17]

2.1.45.  Header field: ETag

   Applicable protocol: http [11]

   Status: standard

   Author/change controller:
      IETF  (iesg@ietf.org)
      Internet Engineering Task Force

   Specification document(s):
      RFC2616 [11]

2.1.46.  Header field: Expect

   Applicable protocol: http [11]

   Status: standard

   Author/change controller:
      IETF  (iesg@ietf.org)
      Internet Engineering Task Force

   Specification document(s):
      RFC2616 [11]

2.1.47.  Header field: Expires

   Applicable protocol: http [11]

   Status: standard

   Author/change controller:
      IETF  (iesg@ietf.org)
      Internet Engineering Task Force

   Specification document(s):
      RFC2616 [11]






Nottingham & Mogul           Informational                     [Page 21]

RFC 4229                   HTTP Header Fields              December 2005

2.1.48.  Header field: Ext

   Applicable protocol: http [11]

   Status: experimental

   Author/change controller:
      Henrik Frystyk Nielsen  (frystyk@microsoft.com)
      Paul J. Leach  (paulle@microsoft.com)
      Scott Lawrence  (lawrence@agranat.com)

   Specification document(s):
      RFC2774 [14]

2.1.49.  Header field: From

   Applicable protocol: http [11]

   Status: standard

   Author/change controller:
      IETF  (iesg@ietf.org)
      Internet Engineering Task Force

   Specification document(s):
      RFC2616 [11]

2.1.50.  Header field: GetProfile

   Applicable protocol: http [11]

   Status: informational

   Author/change controller:
      Pat Hensley  (hensley@firefly.net)
      FireFly Network, Inc.
      Max Metral  (max@firefly.net)
      FireFly Network, Inc.
      Upendra Shardanand  (shard@firefly.net)
      FireFly Network, Inc.
      Donna Converse  (converse@netscape.com)
      Netscape Communications
      Mike Myers  (mmyers@verisign.com)
      Verisign, Inc.

   Specification document(s):
      OPS over HTTP [22]




Nottingham & Mogul           Informational                     [Page 22]

RFC 4229                   HTTP Header Fields              December 2005

2.1.51.  Header field: Host

   Applicable protocol: http [11]

   Status: standard

   Author/change controller:
      IETF  (iesg@ietf.org)
      Internet Engineering Task Force

   Specification document(s):
      RFC2616 [11]

2.1.52.  Header field: IM

   Applicable protocol: http [11]

   Status: standard

   Author/change controller:
      IETF  (iesg@ietf.org)
      Internet Engineering Task Force

   Specification document(s):
      RFC3229 [16]

2.1.53.  Header field: If

   Applicable protocol: http [11]

   Status: standard

   Author/change controller:
      IETF  (iesg@ietf.org)
      Internet Engineering Task Force

   Specification document(s):
      RFC2518 [10]

2.1.54.  Header field: If-Match

   Applicable protocol: http [11]

   Status: standard







Nottingham & Mogul           Informational                     [Page 23]

RFC 4229                   HTTP Header Fields              December 2005


   Author/change controller:
      IETF  (iesg@ietf.org)
      Internet Engineering Task Force

   Specification document(s):
      RFC2616 [11]

2.1.55.  Header field: If-Modified-Since

   Applicable protocol: http [11]

   Status: standard

   Author/change controller:
      IETF  (iesg@ietf.org)
      Internet Engineering Task Force

   Specification document(s):
      RFC2616 [11]

2.1.56.  Header field: If-None-Match

   Applicable protocol: http [11]

   Status: standard

   Author/change controller:
      IETF  (iesg@ietf.org)
      Internet Engineering Task Force

   Specification document(s):
      RFC2616 [11]

2.1.57.  Header field: If-Range

   Applicable protocol: http [11]

   Status: standard

   Author/change controller:
      IETF  (iesg@ietf.org)
      Internet Engineering Task Force

   Specification document(s):
      RFC2616 [11]






Nottingham & Mogul           Informational                     [Page 24]

RFC 4229                   HTTP Header Fields              December 2005

2.1.58.  Header field: If-Unmodified-Since

   Applicable protocol: http [11]

   Status: standard

   Author/change controller:
      IETF  (iesg@ietf.org)
      Internet Engineering Task Force

   Specification document(s):
      RFC2616 [11]

2.1.59.  Header field: Keep-Alive

   Applicable protocol: http [11]

   Status: standard

   Author/change controller:
      IETF  (iesg@ietf.org)
      Internet Engineering Task Force

   Specification document(s):
      RFC2068 [4]

2.1.60.  Header field: Label

   Applicable protocol: http [11]

   Status: standard

   Author/change controller:
      IETF  (iesg@ietf.org)
      Internet Engineering Task Force

   Specification document(s):
      RFC3253 [18]

2.1.61.  Header field: Last-Modified

   Applicable protocol: http [11]

   Status: standard







Nottingham & Mogul           Informational                     [Page 25]

RFC 4229                   HTTP Header Fields              December 2005


   Author/change controller:
      IETF  (iesg@ietf.org)
      Internet Engineering Task Force

   Specification document(s):
      RFC2616 [11]

2.1.62.  Header field: Link

   Applicable protocol: http [11]

   Status: standard

   Author/change controller:
      IETF  (iesg@ietf.org)
      Internet Engineering Task Force

   Specification document(s):
      RFC2068 [4]

2.1.63.  Header field: Location

   Applicable protocol: http [11]

   Status: standard

   Author/change controller:
      IETF  (iesg@ietf.org)
      Internet Engineering Task Force

   Specification document(s):
      RFC2616 [11]

2.1.64.  Header field: Lock-Token

   Applicable protocol: http [11]

   Status: standard

   Author/change controller:
      IETF  (iesg@ietf.org)
      Internet Engineering Task Force

   Specification document(s):
      RFC2518 [10]






Nottingham & Mogul           Informational                     [Page 26]

RFC 4229                   HTTP Header Fields              December 2005

2.1.65.  Header field: MIME-Version

   Applicable protocol: http [11]

   Status: standard

   Author/change controller:
      IETF  (iesg@ietf.org)
      Internet Engineering Task Force

   Specification document(s):
      RFC2616 [11]

2.1.66.  Header field: Man

   Applicable protocol: http [11]

   Status: experimental

   Author/change controller:
      Henrik Frystyk Nielsen  (frystyk@microsoft.com)
      Paul J. Leach  (paulle@microsoft.com)
      Scott Lawrence  (lawrence@agranat.com)

   Specification document(s):
      RFC2774 [14]

2.1.67.  Header field: Max-Forwards

   Applicable protocol: http [11]

   Status: standard

   Author/change controller:
      IETF  (iesg@ietf.org)
      Internet Engineering Task Force

   Specification document(s):
      RFC2616 [11]

2.1.68.  Header field: Meter

   Applicable protocol: http [11]

   Status: standard






Nottingham & Mogul           Informational                     [Page 27]

RFC 4229                   HTTP Header Fields              December 2005


   Author/change controller:
      IETF  (iesg@ietf.org)
      Internet Engineering Task Force

   Specification document(s):
      RFC2227 [6]

2.1.69.  Header field: Negotiate

   Applicable protocol: http [11]

   Status: experimental

   Author/change controller:
      Andrew H. Mutz  (mutz@hpl.hp.com)
      Koen Holtman  (koen@win.tue.nl)

   Specification document(s):
      RFC2295 [7]

2.1.70.  Header field: Opt

   Applicable protocol: http [11]

   Status: experimental

   Author/change controller:
      Henrik Frystyk Nielsen  (frystyk@microsoft.com)
      Paul J. Leach  (paulle@microsoft.com)
      Scott Lawrence  (lawrence@agranat.com)

   Specification document(s):
      RFC2774 [14]

2.1.71.  Header field: Ordering-Type

   Applicable protocol: http [11]

   Status: standard

   Author/change controller:
      IETF  (iesg@ietf.org)
      Internet Engineering Task Force

   Specification document(s):
      RFC3648 [19]





Nottingham & Mogul           Informational                     [Page 28]

RFC 4229                   HTTP Header Fields              December 2005

2.1.72.  Header field: Overwrite

   Applicable protocol: http [11]

   Status: standard

   Author/change controller:
      IETF  (iesg@ietf.org)
      Internet Engineering Task Force

   Specification document(s):
      RFC2518 [10]

2.1.73.  Header field: P3P

   Applicable protocol: http [11]

   Status: standard

   Author/change controller:
      W3C  (web-human@w3.org)
      World Wide Web Consortium

   Specification document(s):
      P3P [23]

2.1.74.  Header field: PEP

   Applicable protocol: http [11]

   Status: deprecated

   Author/change controller:
      Henrik Frystyk Nielsen  (frystyk@w3.org)
      World Wide Web Consortium, MIT Laboratory for Computer Science
      Dan Connolly  (connolly@w3.org)
      World Wide Web Consortium, MIT Laboratory for Computer Science
      Rohit Khare  (khare@w3.org)
      World Wide Web Consortium, MIT Laboratory for Computer Science
      Eric Prud'hommeaux  (eric@w3.org)
      World Wide Web Consortium, MIT Laboratory for Computer Science

   Specification document(s):
      PEP [29]







Nottingham & Mogul           Informational                     [Page 29]

RFC 4229                   HTTP Header Fields              December 2005

2.1.75.  Header field: PICS-Label

   Applicable protocol: http [11]

   Status: standard

   Author/change controller:
      W3C  (web-human@w3.org)
      World Wide Web Consortium

   Specification document(s):
      PICSLabels [24]

2.1.76.  Header field: Pep-Info

   Applicable protocol: http [11]

   Status: deprecated

   Author/change controller:
      Henrik Frystyk Nielsen  (frystyk@w3.org)
      World Wide Web Consortium, MIT Laboratory for Computer Science
      Dan Connolly  (connolly@w3.org)
      World Wide Web Consortium, MIT Laboratory for Computer Science
      Rohit Khare  (khare@w3.org)
      World Wide Web Consortium, MIT Laboratory for Computer Science
      Eric Prud'hommeaux  (eric@w3.org)
      World Wide Web Consortium, MIT Laboratory for Computer Science

   Specification document(s):  PEP [29]

2.1.77.  Header field: Position

      Applicable protocol: http [11]

      Status: standard

      Author/change controller:
         IETF  (iesg@ietf.org)
         Internet Engineering Task Force

      Specification document(s):
         RFC3648 [19]








Nottingham & Mogul           Informational                     [Page 30]

RFC 4229                   HTTP Header Fields              December 2005

2.1.78.  Header field: Pragma

   Applicable protocol: http [11]

   Status: standard

   Author/change controller:
      IETF  (iesg@ietf.org)
      Internet Engineering Task Force

   Specification document(s):
      RFC2616 [11]

2.1.79.  Header field: ProfileObject

   Applicable protocol: http [11]

   Status: informational

   Author/change controller:
      Pat Hensley  (hensley@firefly.net)
      FireFly Network, Inc.
      Max Metral  (max@firefly.net)
      FireFly Network, Inc.
      Upendra Shardanand  (shard@firefly.net)
      FireFly Network, Inc.
      Donna Converse  (converse@netscape.com)
      Netscape Communications
      Mike Myers  (mmyers@verisign.com)
      Verisign, Inc.

   Specification document(s):
      OPS over HTTP [22]

2.1.80.  Header field: Protocol

   Applicable protocol: http [11]

   Status: standard

   Author/change controller:
      W3C  (web-human@w3.org)
      World Wide Web Consortium

   Specification document(s):
      PICSLabels [24]





Nottingham & Mogul           Informational                     [Page 31]

RFC 4229                   HTTP Header Fields              December 2005

2.1.81.  Header field: Protocol-Info

   Applicable protocol: http [11]

   Status: deprecated

   Author/change controller:
      Don Eastlake  (dee@cybercash.com)
      Rohit Khare  (khare@w3.org)
      Jim Miller  (jmiller@w3.org)

   Specification document(s):
      Selecting Payment Mechanisms [26]

2.1.82.  Header field: Protocol-Query

   Applicable protocol: http [11]

   Status: deprecated

   Author/change controller:
      Don Eastlake  (dee@cybercash.com)
      Rohit Khare  (khare@w3.org)
      Jim Miller  (jmiller@w3.org)

   Specification document(s):
      Selecting Payment Mechanisms [26]

2.1.83.  Header field: Protocol-Request

   Applicable protocol: http [11]

   Status: standard

   Author/change controller:
      W3C  (web-human@w3.org)
      World Wide Web Consortium

   Specification document(s):
      PICSLabels [24]

2.1.84.  Header field: Proxy-Authenticate

   Applicable protocol: http [11]

   Status: standard





Nottingham & Mogul           Informational                     [Page 32]

RFC 4229                   HTTP Header Fields              December 2005


   Author/change controller:
      IETF  (iesg@ietf.org)
      Internet Engineering Task Force

   Specification document(s):
      RFC2616 [11]

2.1.85.  Header field: Proxy-Authentication-Info

   Applicable protocol: http [11]

   Status: standard

   Author/change controller:
      IETF  (iesg@ietf.org)
      Internet Engineering Task Force

   Specification document(s):
      RFC2617 [12]

2.1.86.  Header field: Proxy-Authorization

   Applicable protocol: http [11]

   Status: standard

   Author/change controller:
      IETF  (iesg@ietf.org)
      Internet Engineering Task Force

   Specification document(s):
      RFC2616 [11]

2.1.87.  Header field: Proxy-Features

   Applicable protocol: http [11]

   Status: informational

   Author/change controller:
      Phillip M. Hallam-Baker  (hallam@w3.org)
      W3C

   Specification document(s):
      Proxy Notification [27]






Nottingham & Mogul           Informational                     [Page 33]

RFC 4229                   HTTP Header Fields              December 2005

2.1.88.  Header field: Proxy-Instruction

   Applicable protocol: http [11]

   Status: informational

   Author/change controller:
      Phillip M. Hallam-Baker  (hallam@w3.org)
      W3C

   Specification document(s):
      Proxy Notification [27]

2.1.89.  Header field: Public

   Applicable protocol: http [11]

   Status: standard

   Author/change controller:
      IETF  (iesg@ietf.org)
      Internet Engineering Task Force

   Specification document(s):
      RFC2068 [4]

2.1.90.  Header field: Range

   Applicable protocol: http [11]

   Status: standard

   Author/change controller:
      IETF  (iesg@ietf.org)
      Internet Engineering Task Force

   Specification document(s):
      RFC2616 [11]

2.1.91.  Header field: Referer

   Applicable protocol: http [11]

   Status: standard







Nottingham & Mogul           Informational                     [Page 34]

RFC 4229                   HTTP Header Fields              December 2005


   Author/change controller:
      IETF  (iesg@ietf.org)
      Internet Engineering Task Force

   Specification document(s):
      RFC2616 [11]

2.1.92.  Header field: Retry-After

   Applicable protocol: http [11]

   Status: standard

   Author/change controller:
      IETF  (iesg@ietf.org)
      Internet Engineering Task Force

   Specification document(s):
      RFC2616 [11]

2.1.93.  Header field: Safe

   Applicable protocol: http [11]

   Status: experimental

   Author/change controller:
      Koen Holtman  (koen@win.tue.nl)

   Specification document(s):
      RFC2310 [8]

2.1.94.  Header field: Security-Scheme

   Applicable protocol: http [11]

   Status: experimental

   Author/change controller:
      Eric Rescorla  (ekr@rtfm.com)
      A. Schiffman  (ams@terisa.com)

   Specification document(s):
      RFC2660 [13]







Nottingham & Mogul           Informational                     [Page 35]

RFC 4229                   HTTP Header Fields              December 2005

2.1.95.  Header field: Server

   Applicable protocol: http [11]

   Status: standard

   Author/change controller:
      IETF  (iesg@ietf.org)
      Internet Engineering Task Force

   Specification document(s):
      RFC2616 [11]

2.1.96.  Header field: Set-Cookie

   Applicable protocol: http [11]

   Status: standard

   Author/change controller:
      IETF  (iesg@ietf.org)
      Internet Engineering Task Force

   Specification document(s):
      RFC2109 [5]

2.1.97.  Header field: Set-Cookie2

   Applicable protocol: http [11]

   Status: standard

   Author/change controller:
      IETF  (iesg@ietf.org)
      Internet Engineering Task Force

   Specification document(s):
      RFC2965 [15]

2.1.98.  Header field: SetProfile

   Applicable protocol: http [11]

   Status: informational







Nottingham & Mogul           Informational                     [Page 36]

RFC 4229                   HTTP Header Fields              December 2005


   Author/change controller:
      Pat Hensley  (hensley@firefly.net)
      FireFly Network, Inc.
      Max Metral  (max@firefly.net)
      FireFly Network, Inc.
      Upendra Shardanand  (shard@firefly.net)
      FireFly Network, Inc.
      Donna Converse  (converse@netscape.com)
      Netscape Communications
      Mike Myers  (mmyers@verisign.com)
      Verisign, Inc.

   Specification document(s):
      OPS over HTTP [22]

2.1.99.  Header field: SoapAction

   Applicable protocol: http [11]

   Status: informational

   Author/change controller:
      Don Box  (dbox@develop.com)
      DevelopMentor
      David Ehnebuske  (davide@us.ibm.com)
      IBM
      Gopal Kakivaya  (gopalk@microsoft.com)
      Microsoft
      Andrew Layman  (andrewl@microsoft.com)
      Microsoft
      Noah Mendelsohn  (Noah_Mendelsohn@lotus.com)
      Lotus Development Corp.
      Hernik Frystyk Nielsen  (frystyk@microsoft.com)
      Microsoft
      Satish Thatte  (satisht@microsoft.com)
      Microsoft
      Dave Winer  (dave@userland.com)
      UserLand Software, Inc.

   Specification document(s):
      SOAP [28]

2.1.100.  Header field: Status-URI

   Applicable protocol: http [11]

   Status: standard




Nottingham & Mogul           Informational                     [Page 37]

RFC 4229                   HTTP Header Fields              December 2005


   Author/change controller:
      IETF  (iesg@ietf.org)
      Internet Engineering Task Force

   Specification document(s):
      RFC2518 [10]

2.1.101.  Header field: Surrogate-Capability

   Applicable protocol: http [11]

   Status: informational

   Author/change controller:
      Mark Nottingham  (mnot@akamai.com)
      Akamai
      Xiang Liu  (xiang.liu@oracle.com)
      Oracle

   Specification document(s):
      edge-arch [25]

2.1.102.  Header field: Surrogate-Control

   Applicable protocol: http [11]

   Status: informational

   Author/change controller:
      Mark Nottingham  (mnot@akamai.com)
      Akamai
      Xiang Liu  (xiang.liu@oracle.com)
      Oracle

   Specification document(s):
      edge-arch [25]

2.1.103.  Header field: TCN

   Applicable protocol: http [11]

   Status: experimental

   Author/change controller:
      Andrew H. Mutz  (mutz@hpl.hp.com)
      Koen Holtman  (koen@win.tue.nl)





Nottingham & Mogul           Informational                     [Page 38]

RFC 4229                   HTTP Header Fields              December 2005


   Specification document(s):
      RFC2295 [7]

2.1.104.  Header field: TE

   Applicable protocol: http [11]

   Status: standard

   Author/change controller:
      IETF  (iesg@ietf.org)
      Internet Engineering Task Force

   Specification document(s):
      RFC2616 [11]

2.1.105.  Header field: Timeout

   Applicable protocol: http [11]

   Status: standard

   Author/change controller:
      IETF  (iesg@ietf.org)
      Internet Engineering Task Force

   Specification document(s):
      RFC2518 [10]

2.1.106.  Header field: Trailer

   Applicable protocol: http [11]

   Status: standard

   Author/change controller:
      IETF  (iesg@ietf.org)
      Internet Engineering Task Force

   Specification document(s):
      RFC2616 [11]

2.1.107.  Header field: Transfer-Encoding

   Applicable protocol: http [11]

   Status: standard




Nottingham & Mogul           Informational                     [Page 39]

RFC 4229                   HTTP Header Fields              December 2005


   Author/change controller:
      IETF  (iesg@ietf.org)
      Internet Engineering Task Force

   Specification document(s):
      RFC2616 [11]

2.1.108.  Header field: URI

   Applicable protocol: http [11]

   Status: standard

   Author/change controller:
      IETF  (iesg@ietf.org)
      Internet Engineering Task Force

   Specification document(s):
      RFC2068 [4]

2.1.109.  Header field: Upgrade

   Applicable protocol: http [11]

   Status: standard

   Author/change controller:
      IETF  (iesg@ietf.org)
      Internet Engineering Task Force

   Specification document(s):
      RFC2616 [11]

2.1.110.  Header field: User-Agent

   Applicable protocol: http [11]

   Status: standard

   Author/change controller:
      IETF  (iesg@ietf.org)
      Internet Engineering Task Force

   Specification document(s):
      RFC2616 [11]






Nottingham & Mogul           Informational                     [Page 40]

RFC 4229                   HTTP Header Fields              December 2005

2.1.111.  Header field: Variant-Vary

   Applicable protocol: http [11]

   Status: experimental

   Author/change controller:
      Andrew H. Mutz  (mutz@hpl.hp.com)
      Koen Holtman  (koen@win.tue.nl)

   Specification document(s):
      RFC2295 [7]

2.1.112.  Header field: Vary

   Applicable protocol: http [11]

   Status: standard

   Author/change controller:
      IETF  (iesg@ietf.org)
      Internet Engineering Task Force

   Specification document(s):
      RFC2616 [11]

2.1.113.  Header field: Via

   Applicable protocol: http [11]

   Status: standard

   Author/change controller:
      IETF  (iesg@ietf.org)
      Internet Engineering Task Force

   Specification document(s):
      RFC2616 [11]

2.1.114.  Header field: WWW-Authenticate

   Applicable protocol: http [11]

   Status: standard







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RFC 4229                   HTTP Header Fields              December 2005


   Author/change controller:
      IETF  (iesg@ietf.org)
      Internet Engineering Task Force

   Specification document(s):
      RFC2616 [11]

2.1.115.  Header field: Want-Digest

   Applicable protocol: http [11]

   Status: standard

   Author/change controller:
      IETF  (iesg@ietf.org)
      Internet Engineering Task Force

   Specification document(s):
      RFC3230 [17]

2.1.116.  Header field: Warning

   Applicable protocol: http [11]

   Status: standard

   Author/change controller:
      IETF  (iesg@ietf.org)
      Internet Engineering Task Force

   Specification document(s):
      RFC2616 [11]



















Nottingham & Mogul           Informational                     [Page 42]

RFC 4229                   HTTP Header Fields              December 2005

2.2.  Provisional HTTP Header Field Submissions

   Header name             Protocol
   -----------             --------
   Compliance                http
   Content-Transfer-Encoding http
   Cost                      http
   Message-ID                http
   Non-Compliance            http
   Optional                  http
   Resolution-Hint           http
   Resolver-Location         http
   SubOK                     http
   Subst                     http
   Title                     http
   UA-Color                  http
   UA-Media                  http
   UA-Pixels                 http
   UA-Resolution             http
   UA-Windowpixels           http
   Version                   http

2.2.1.  Header field: Compliance

   Applicable protocol: http [11]

   Status: provisional

   Author/change controller:  Jeffrey C. Mogul  (mogul@wrl.dec.com)
      Western Research Laboratory, Digital Equipment Corporation Josh
      Cohen  (josh@netscape.com) Netscape Communications Corporation
      Scott Lawrence  (lawrence@agranat.com) Agranat Systems, Inc.

   Specification document(s):
      OPTIONS messages [31]

2.2.2.  Header field: Content-Transfer-Encoding

   Applicable protocol: http [11]

   Status: provisional

   Author/change controller:
      Tim Berners-Lee  (timbl@w3.org)
      MIT Laboratory for Computer Science






Nottingham & Mogul           Informational                     [Page 43]

RFC 4229                   HTTP Header Fields              December 2005


   Specification document(s):
      Object Headers [2]

2.2.3.  Header field: Cost

   Applicable protocol: http [11]

   Status: provisional

   Author/change controller:
      Tim Berners-Lee  (timbl@w3.org)
      MIT Laboratory for Computer Science

   Specification document(s):
      Object Headers [2]

2.2.4.  Header field: Message-ID

   Applicable protocol: http [11]

   Status: provisional

   Author/change controller:
      Tim Berners-Lee  (timbl@w3.org)
      MIT Laboratory for Computer Science

   Specification document(s):
      Object Headers [2]

2.2.5.  Header field: Non-Compliance

   Applicable protocol: http [11]

   Status: provisional

   Author/change controller:  Jeffrey C. Mogul  (mogul@wrl.dec.com)
      Western Research Laboratory, Digital Equipment Corporation Josh
      Cohen  (josh@netscape.com) Netscape Communications Corporation
      Scott Lawrence  (lawrence@agranat.com) Agranat Systems, Inc.

   Specification document(s):
      OPTIONS messages [31]

2.2.6.  Header field: Optional

   Applicable protocol: http [11]

   Status: provisional



Nottingham & Mogul           Informational                     [Page 44]

RFC 4229                   HTTP Header Fields              December 2005


   Author/change controller:
      John Mallery  (jcma@ai.mit.edu)
      MIT Artificial Intelligence Laboratory
      Lewis Girod  (girod@lcs.mit.edu)
      MIT Laboratory for Computer Science
      Benjie Chen  (benjie@lcs.mit.edu)
      MIT Laboratory for Computer Science
      Henrik Frystyk Nielsen  (frystyk@w3.org)
      World Wide Web Consortium

   Specification document(s):
      WIRE [32]

2.2.7.  Header field: Resolution-Hint

   Applicable protocol: http [11]

   Status: provisional

   Author/change controller:
      John Mallery  (jcma@ai.mit.edu)
      MIT Artificial Intelligence Laboratory
      Lewis Girod  (girod@lcs.mit.edu)
      MIT Laboratory for Computer Science
      Benjie Chen  (benjie@lcs.mit.edu)
      MIT Laboratory for Computer Science
      Henrik Frystyk Nielsen  (frystyk@w3.org)
      World Wide Web Consortium

   Specification document(s):
      WIRE [32]

2.2.8.  Header field: Resolver-Location

   Applicable protocol: http [11]

   Status: provisional

   Author/change controller:
      John Mallery  (jcma@ai.mit.edu)
      MIT Artificial Intelligence Laboratory
      Lewis Girod  (girod@lcs.mit.edu)
      MIT Laboratory for Computer Science
      Benjie Chen  (benjie@lcs.mit.edu)
      MIT Laboratory for Computer Science
      Henrik Frystyk Nielsen  (frystyk@w3.org)
      World Wide Web Consortium




Nottingham & Mogul           Informational                     [Page 45]

RFC 4229                   HTTP Header Fields              December 2005


   Specification document(s):
      WIRE [32]

2.2.9.  Header field: SubOK

   Applicable protocol: http [11]

   Status: provisional

   Author/change controller:  Jeffrey C. Mogul  (mogul@wrl.dec.com)
      Western Research Laboratory, Digital Equipment Corporation Arthur
      van Hoff  (avh@marimba.com) Marimba, Inc.

   Specification document(s):
      Duplicate Suppression [33]

2.2.10.  Header field: Subst

   Applicable protocol: http [11]

   Status: provisional

   Author/change controller:  Jeffrey C. Mogul  (mogul@wrl.dec.com)
      Western Research Laboratory, Digital Equipment Corporation Arthur
      van Hoff  (avh@marimba.com) Marimba, Inc.

   Specification document(s):
      Duplicate Suppression [33]

2.2.11.  Header field: Title

   Applicable protocol: http [11]

   Status: provisional

   Author/change controller:
      Tim Berners-Lee  (timbl@w3.org)
      MIT Laboratory for Computer Science

   Specification document(s):
      Object Headers [2]

2.2.12.  Header field: UA-Color

   Applicable protocol: http [11]

   Status: provisional




Nottingham & Mogul           Informational                     [Page 46]

RFC 4229                   HTTP Header Fields              December 2005


   Author/change controller:
      Larry Masinter  (LMM@acm.org)
      Adobe Systems
      Lou Montulli  (montulli@netscape.com)
      Netscape Communications Corp.
      Andrew H. Mutz  (mutz@hpl.hp.com)
      Hewlett-Packard Company

   Specification document(s):
      UA Attributes [30]

2.2.13.  Header field: UA-Media

   Applicable protocol: http [11]

   Status: provisional

   Author/change controller:
      Larry Masinter  (LMM@acm.org)
      Adobe Systems
      Lou Montulli  (montulli@netscape.com)
      Netscape Communications Corp.
      Andrew H. Mutz  (mutz@hpl.hp.com)
      Hewlett-Packard Company

   Specification document(s):
      UA Attributes [30]

2.2.14.  Header field: UA-Pixels

   Applicable protocol: http [11]

   Status: provisional

   Author/change controller:
      Larry Masinter  (LMM@acm.org)
      Adobe Systems
      Lou Montulli  (montulli@netscape.com)
      Netscape Communications Corp.
      Andrew H. Mutz  (mutz@hpl.hp.com)
      Hewlett-Packard Company

   Specification document(s):
      UA Attributes [31]







Nottingham & Mogul           Informational                     [Page 47]

RFC 4229                   HTTP Header Fields              December 2005

2.2.15.  Header field: UA-Resolution

   Applicable protocol: http [11]

   Status: provisional

   Author/change controller:
      Larry Masinter  (LMM@acm.org)
      Adobe Systems
      Lou Montulli  (montulli@netscape.com)
      Netscape Communications Corp.
      Andrew H. Mutz  (mutz@hpl.hp.com)
      Hewlett-Packard Company

   Specification document(s):
      UA Attributes [30]

2.2.16.  Header field: UA-Windowpixels

   Applicable protocol: http [11]

   Status: provisional

   Author/change controller:
      Larry Masinter  (LMM@acm.org)
      Adobe Systems
      Lou Montulli  (montulli@netscape.com)
      Netscape Communications Corp.
      Andrew H. Mutz  (mutz@hpl.hp.com)
      Hewlett-Packard Company

   Specification document(s):
      UA Attributes [30]

2.2.17.  Header field: Version

   Applicable protocol: http [11]

   Status: provisional

   Author/change controller:
      Tim Berners-Lee  (timbl@w3.org)
      MIT Laboratory for Computer Science

   Specification document(s):
      Object Headers [2]





Nottingham & Mogul           Informational                     [Page 48]

RFC 4229                   HTTP Header Fields              December 2005

3.  IANA Considerations

   This specification provides initial registrations of HTTP header
   fields in the "Permanent Message Header Field Registry", defined by
   Registration Procedures for Message Header Fields [1].

   It also provides initial submissions of HTTP header fields in the
   "Provisional Message Header Field Repository", defined by the same
   document.

4.  Security Considerations

   No security considerations are introduced by this document beyond
   those already inherent in use of the HTTP header fields referenced.

5.  Acknowledgements

   The authors would like to thank Graham Klyne for his work in defining
   the message header registries, his input and help in preparing this
   document, and the registry generation software.

6.  Informative References

   [1]   Klyne, G., Nottingham, M., and J. Mogul, "Registration
         Procedures for Message Header Fields", BCP 90, RFC 3864,
         September 2004.

   [2]   Berners-Lee, T., "Object Header lines in HTTP", May 1994,
         <http://www.w3.org/Protocols/HTTP/Object_Headers.html>.

   [3]   Berners-Lee, T., Fielding, R., and H. Nielsen, "Hypertext
         Transfer Protocol -- HTTP/1.0", RFC 1945, May 1996.

   [4]   Fielding, R., Gettys, J., Mogul, J., Nielsen, H., and T.
         Berners-Lee, "Hypertext Transfer Protocol -- HTTP/1.1", RFC
         2068, January 1997.

   [5]   Kristol, D. and L. Montulli, "HTTP State Management Mechanism",
         RFC 2109, February 1997.

   [6]   Mogul, J. and P. Leach, "Simple Hit-Metering and Usage-Limiting
         for HTTP", RFC 2227, October 1997.

   [7]   Holtman, K. and A. Mutz, "Transparent Content Negotiation in
         HTTP", RFC 2295, March 1998.

   [8]   Holtman, K., "The Safe Response Header Field", RFC 2310, April
         1998.



Nottingham & Mogul           Informational                     [Page 49]

RFC 4229                   HTTP Header Fields              December 2005


   [9]   Masinter, L., "Hyper Text Coffee Pot Control Protocol
         (HTCPCP/1.0)", RFC 2324, April 1998.

   [10]  Goland, Y., Whitehead, E., Faizi, A., Carter, S., and D.
         Jensen, "HTTP Extensions for Distributed Authoring -- WEBDAV",
         RFC 2518, February 1999.

   [11]  Fielding, R., Gettys, J., Mogul, J., Frystyk, H., Masinter, L.,
         Leach, P., and T. Berners-Lee, "Hypertext Transfer Protocol --
         HTTP/1.1", RFC 2616, June 1999.

   [12]  Franks, J., Hallam-Baker, P., Hostetler, J., Lawrence, S.,
         Leach, P., Luotonen, A., and L. Stewart, "HTTP Authentication:
         Basic and Digest Access Authentication", RFC 2617, June 1999.

   [13]  Rescorla, E. and A. Schiffman, "The Secure HyperText Transfer
         Protocol", RFC 2660, August 1999.

   [14]  Nielsen, H., Leach, P., and S. Lawrence, "An HTTP Extension
         Framework", RFC 2774, February 2000.

   [15]  Kristol, D. and L. Montulli, "HTTP State Management Mechanism",
         RFC 2965, October 2000.

   [16]  Mogul, J., Krishnamurthy, B., Douglis, F., Feldmann, A.,
         Goland, Y., van Hoff, A., and D. Hellerstein, "Delta encoding
         in HTTP", RFC 3229, January 2002.

   [17]  Mogul, J. and A. Van Hoff, "Instance Digests in HTTP", RFC
         3230, January 2002.

   [18]  Clemm, G., Amsden, J., Ellison, T., Kaler, C., and J.
         Whitehead, "Versioning Extensions to WebDAV (Web Distributed
         Authoring and Versioning)", RFC 3253, March 2002.

   [19]  Whitehead, J. and J. Reschke, Ed., "Web Distributed Authoring
         and Versioning (WebDAV) Ordered Collections Protocol", RFC
         3648, December 2003.

   [20]  Hoff, A., Payne, J., Hapner, M., Carter, S., and M. Medin, "The
         HTTP Distribution and Replication Protocol", W3C NOTE NOTE-
         drp-19970825, August 1997.

   [21]  Raggett, D., Hors, A., and I. Jacobs, "HTML 4.01
         Specification", W3C REC REC-html401-19991224, December 1999.






Nottingham & Mogul           Informational                     [Page 50]

RFC 4229                   HTTP Header Fields              December 2005


   [22]  Hensley, P., Metral, M., Shardanand, U., Converse, D., and M.
         Myers, "Implementation of OPS Over HTTP", W3C NOTE NOTE-OPS-
         OverHTTP, June 1997.

   [23]  Marchiori, M., "The Platform for Privacy Preferences 1.0
         (P3P1.0) Specification", W3C REC REC-P3P-20020416, April 2002.

   [24]  Krauskopf, T., Miller, J., Resnick, P., and W. Treese, "PICS
         1.1 Label Distribution -- Label Syntax and Communication
         Protocols", W3C REC REC-PICS-labels-961031, October 1996.

   [25]  Nottingham, M. and X. Liu, "Edge Architecture Specification",
         W3C NOTE NOTE-edge-arch-20010804, August 2001.

   [26]  Chung, E. and D. Dardailler, "White Paper: Joint Electronic
         Payment Initiative", W3C NOTE NOTE-jepi-970519, May 1997.

   [27]  Hallam-Baker, P., "Notification for Proxy Caches", W3C NOTE WD-
         proxy-960221, February 1996.

   [28]  Box, D., Ehnebuske, D., Kakivaya, G., Layman, A., Mendelsohn,
         N., Nielsen, H., Thatte, S., and D. Winer, "Simple Object
         Access Protocol (SOAP) 1.1", W3C NOTE NOTE-SOAP-20000508, May
         2000.

   [29]  Connolly, D., Prod'hommeaux, E., Nielsen, H., and R. Khare,
         "PEP Specification: an Extension Mechanism for HTTP", Nov 1998,
         <http://www.w3.org/TR/WD-http-pep>.

   [30]  Masinter, L., Montulli, L., and A. Mutz, "User-Agent Display
         Attributes Headers", Work in Progress, November 1996.

   [31]  Mogul, J., Cohen, J., and S. Lawrence, "Specification of
         HTTP/1.1 OPTIONS messages", Work in Progress, August 1997.

   [32]  Girod, L., Chen, B., Henrik, H., and J. Mallery, "WIRE - W3
         Identifier Resolution Extensions", Work in Progress, March
         1998.

   [33]  Mogul, J. and A. van Hoff, "Duplicate Suppression in HTTP",
         Work in Progress, April 1998.










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RFC 4229                   HTTP Header Fields              December 2005

Authors' Addresses

   Mark Nottingham

   EMail: mnot@pobox.com
   URI:   http://www.mnot.net/


   Jeffrey C. Mogul
   HP Labs
   1501 Page Mill Road
   Palo Alto, CA  94304
   US

   EMail: JeffMogul@acm.org




































Nottingham & Mogul           Informational                     [Page 52]

RFC 4229                   HTTP Header Fields              December 2005

Full Copyright Statement

   Copyright (C) The Internet Society (2005).

   This document is subject to the rights, licenses and restrictions
   contained in BCP 78, and except as set forth therein, the authors
   retain all their rights.

   This document and the information contained herein are provided on an
   "AS IS" basis and THE CONTRIBUTOR, THE ORGANIZATION HE/SHE REPRESENTS
   OR IS SPONSORED BY (IF ANY), THE INTERNET SOCIETY AND THE INTERNET
   ENGINEERING TASK FORCE DISCLAIM ALL WARRANTIES, EXPRESS OR IMPLIED,
   INCLUDING BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE
   INFORMATION HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED
   WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.

Intellectual Property

   The IETF takes no position regarding the validity or scope of any
   Intellectual Property Rights or other rights that might be claimed to
   pertain to the implementation or use of the technology described in
   this document or the extent to which any license under such rights
   might or might not be available; nor does it represent that it has
   made any independent effort to identify any such rights.  Information
   on the procedures with respect to rights in RFC documents can be
   found in BCP 78 and BCP 79.

   Copies of IPR disclosures made to the IETF Secretariat and any
   assurances of licenses to be made available, or the result of an
   attempt made to obtain a general license or permission for the use of
   such proprietary rights by implementers or users of this
   specification can be obtained from the IETF on-line IPR repository at
   http://www.ietf.org/ipr.

   The IETF invites any interested party to bring to its attention any
   copyrights, patents or patent applications, or other proprietary
   rights that may cover technology that may be required to implement
   this standard.  Please address the information to the IETF at ietf-
   ipr@ietf.org.

Acknowledgement

   Funding for the RFC Editor function is currently provided by the
   Internet Society.







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