view Side-By-Side changes

Network Working Group                                           G. Klyne
Internet-Draft                                              Nine by Nine
Expires: August 19, October 12, 2004                                       J. Palme
                                                Stockholm University/KTH
                                                       February 19,
                                                          April 13, 2004


              Registration of mail and MIME header fields
                       draft-klyne-hdrreg-mail-02
                       draft-klyne-hdrreg-mail-03

Status of this Memo

   This document is an Internet-Draft and is in full conformance with
   all provisions of Section 10 of RFC2026.

   Internet-Drafts are working documents of the Internet Engineering
   Task Force (IETF), its areas, and its working groups. Note that other
   groups may also distribute working documents as Internet-Drafts.

   Internet-Drafts are draft documents valid for a maximum of six months
   and may be updated, replaced, or obsoleted by other documents at any
   time. It is inappropriate to use Internet-Drafts as reference
   material or to cite them other than as "work in progress."

   The list of current Internet-Drafts can be accessed at http://
   www.ietf.org/ietf/1id-abstracts.txt.

   The list of Internet-Draft Shadow Directories can be accessed at
   http://www.ietf.org/shadow.html.

   This Internet-Draft will expire on August 19, October 12, 2004.

Copyright Notice

   Copyright (C) The Internet Society (2004). All Rights Reserved.

Abstract

   This document defines the initial IANA registration for permanent
   mail and MIME message header fields, per [[[RFC XXXX]]] [1].

Discussion of this document

   Please send comments to <ietf-822@imc.org>. To subscribe to this
   list, send a message with the body 'subscribe' to
   <ietf-822-request@imc.org>.






Klyne & Palme           Expires August 19, October 12, 2004                [Page 1]

Internet-Draft       Mail/MIME header registration         February            April 2004


Table of Contents

   1.     Introduction . . . . . . . . . . . . . . . . . . . . . . .   4   5
   1.1    Structure of this document . . . . . . . . . . . . . . . .   4   5
   1.2    Document terminology and conventions . . . . . . . . . . .   4   5
   2.     Registration templates . . . . . . . . . . . . . . . . . .   4   5
   2.1    Permanent mail header field registrations  . . . . . . . .   4   5
   2.1.1  Header field: Date . . . . . . . . . . . . . . . . . . . .   6   8
   2.1.2  Header field: From . . . . . . . . . . . . . . . . . . . .   7   8
   2.1.3  Header field: Sender . . . . . . . . . . . . . . . . . . .   7   8
   2.1.4  Header field: Reply-To . . . . . . . . . . . . . . . . . .   8   9
   2.1.5  Header field: To . . . . . . . . . . . . . . . . . . . . .   8   9
   2.1.6  Header field: Cc . . . . . . . . . . . . . . . . . . . . .   9  10
   2.1.7  Header field: Bcc  . . . . . . . . . . . . . . . . . . . .   9  10
   2.1.8  Header field: Message-ID . . . . . . . . . . . . . . . . .  10  11
   2.1.9  Header field: In-Reply-To  . . . . . . . . . . . . . . . .  10  11
   2.1.10 Header field: References . . . . . . . . . . . . . . . . .  11  12
   2.1.11 Header field: Subject  . . . . . . . . . . . . . . . . . .  11  12
   2.1.12 Header field: Comments . . . . . . . . . . . . . . . . . .  12  13
   2.1.13 Header field: Keywords . . . . . . . . . . . . . . . . . .  12  13
   2.1.14 Header field: Resent-Date  . . . . . . . . . . . . . . . .  13  14
   2.1.15 Header field: Resent-From  . . . . . . . . . . . . . . . .  13  14
   2.1.16 Header field: Resent-Sender  . . . . . . . . . . . . . . .  14
   2.1.17 Header field: Resent-To  . . . . . . . . . . . . . . . . .  14  15
   2.1.18 Header field: Resent-Cc  . . . . . . . . . . . . . . . . .  15
   2.1.19 Header field: Resent-Bcc . . . . . . . . . . . . . . . . .  15  16
   2.1.20 Header field: Resent-Message-ID Resent-Reply-To  . . . . . . . . . . . . . .  16
   2.1.21 Header field: Return-Path  . . . Resent-Message-ID  . . . . . . . . . . . . .  16  17
   2.1.22 Header field: Received . . Return-Path  . . . . . . . . . . . . . . . .  16  17
   2.1.23 Header field: Disposition-Notification-To Received . . . . . . . . . . . .  17
   2.1.24 Header field: Disposition-Notification-Options . . . . . .  17
   2.1.25
   2.1.24 Header field: Original-Recipient Disposition-Notification-To  . . . . . . . .  18
   2.1.25 Header field: Disposition-Notification-Options . . . . . .  18
   2.1.26 Header field: Originator . . Accept-Language  . . . . . . . . . . . . . . .  18  19
   2.1.27 Header field: PICS-Label . . . . . Original-Message-ID  . . . . . . . . . . . .  19
   2.1.28 Header field: Encoding . PICS-Label . . . . . . . . . . . . . . . . .  19  20
   2.1.29 Header field: List-Archive Encoding . . . . . . . . . . . . . . . . . .  20
   2.1.30 Header field: List-Help  . List-Archive . . . . . . . . . . . . . . . .  20  21
   2.1.31 Header field: List-ID  . List-Help  . . . . . . . . . . . . . . . . .  21
   2.1.32 Header field: List-Owner List-ID  . . . . . . . . . . . . . . . . .  21 .  22
   2.1.33 Header field: List-Post List-Owner . . . . . . . . . . . . . . . . .  22
   2.1.34 Header field: List-Subscribe List-Post  . . . . . . . . . . . . . . .  22 . .  23
   2.1.35 Header field: List-Unsubscribe List-Subscribe . . . . . . . . . . . . . . .  23
   2.1.36 Header field: Message-Context List-Unsubscribe . . . . . . . . . . . . . .  23  24
   2.1.37 Header field: DL-Expansion-History Message-Context  . . . . . . . . . . . . . .  24
   2.1.38 Header field: Alternate-Recipient DL-Expansion-History . . . . . . . . . . . .  24
   2.1.39 Header field: Original-Encoded-Information-Types . . . Alternate-Recipient  . .  25
   2.1.40 Header field: Content-Return . . . . . . . . . .  25
   2.1.40 Header field: Original-Encoded-Information-Types . . . . .  25
   2.1.41 Header field: Generate-Delivery-Report Content-Return . . . . . . . . . . . . . . .  26



Klyne & Palme           Expires August 19, October 12, 2004                [Page 2]

Internet-Draft       Mail/MIME header registration         February            April 2004


   2.1.42 Header field: Prevent-NonDelivery-Report Generate-Delivery-Report . . . . . . . . . .  26
   2.1.43 Header field: Obsoletes  . . . . . . . . Prevent-NonDelivery-Report . . . . . . . . .  27
   2.1.44 Header field: Content-Identifier Obsoletes  . . . . . . . . . . . . . . . . .  27
   2.1.45 Header field: Delivery-Date Supersedes . . . . . . . . . . . . . . . . .  28
   2.1.46 Header field: Expiry-Date  . . . Content-Identifier . . . . . . . . . . . . .  28
   2.1.47 Header field: Reply-By . . . Delivery-Date  . . . . . . . . . . . . . . .  29
   2.1.48 Header field: Importance . Expiry-Date  . . . . . . . . . . . . . . . .  29
   2.1.49 Header field: Incomplete-Copy Expires  . . . . . . . . . . . . . . . . . .  30
   2.1.50 Header field: Priority Reply-By . . . . . . . . . . . . . . . . . .  30
   2.1.51 Header field: Sensitivity Importance . . . . . . . . . . . . . . . . .  31
   2.1.52 Header field: Language . . . . Incomplete-Copy  . . . . . . . . . . . . . .  32  31
   2.1.53 Header field: Conversion Priority . . . . . . . . . . . . . . . . .  32 .  31
   2.1.54 Header field: Conversion-With-Loss Sensitivity  . . . . . . . . . . . .  33 . . . .  32
   2.1.55 Header field: Message-Type Language . . . . . . . . . . . . . . . .  33 . .  32
   2.1.56 Header field: Autoforwarded Conversion . . . . . . . . . . . . . . .  34 . .  33
   2.1.57 Header field: Discarded-X400-IPMS-Extensions . . Conversion-With-Loss . . . . .  34
   2.1.58 Header field: Discarded-X400-MTS-Extensions . . . . . . .  35
   2.1.59  33
   2.1.58 Header field: Disclose-Recipients Message-Type . . . . . . . . . . . .  35
   2.2    Permanent MIME header field registrations . . . .  34
   2.1.59 Header field: Autosubmitted  . . . .  36
   2.2.1 . . . . . . . . . . .  34
   2.1.60 Header field: MIME-Version Autoforwarded  . . . . . . . . . . . . . . .  35
   2.1.61 Header field: Discarded-X400-IPMS-Extensions . .  36
   2.2.2 . . . . .  35
   2.1.62 Header field: Content-ID Discarded-X400-MTS-Extensions  . . . . . . .  36
   2.1.63 Header field: Disclose-Recipients  . . . . . . . . . . . .  37
   2.2.3  36
   2.1.64 Header field: Content-Description Deferred-Delivery  . . . . . . . . . . . . .  37
   2.2.4
   2.1.65 Header field: Content-Transfer-Encoding Latest-Delivery-Time . . . . . . . . .  38
   2.2.5 . . .  37
   2.1.66 Header field: Content-Type . Originator-Return-Address  . . . . . . . . .  38
   2.1.67 Header field: X400-Content-Identifier  . . . . . .  38
   2.2.6  Header field: Content-Base . . . .  38
   2.1.68 Header field: X400-Content-Return  . . . . . . . . . . . .  39
   2.2.7
   2.1.69 Header field: Content-Location . X400-Content-Type  . . . . . . . . . . . . .  39
   2.2.8
   2.1.70 Header field: Content-features . X400-MTS-Identifier  . . . . . . . . . . . . .  40
   2.2.9  39
   2.1.71 Header field: Content-Disposition X400-Originator  . . . . . . . . . . . . . .  40
   2.2.10
   2.1.72 Header field: Content-Language X400-Received  . . . . . . . . . . . . . .  41
   2.2.11 .  40
   2.1.73 Header field: Content-Alternative X400-Recipients  . . . . . . . . . . . . . .  41
   2.2.12
   2.1.74 Header field: Content-MD5 X400-Trace . . . . . . . . . . . . . . . .  42
   3.     IANA considerations .  41
   2.2    Permanent MIME header field registrations  . . . . . . . .  42
   2.2.1  Header field: MIME-Version . . . . . . . . . .  42
   4.     Security considerations . . . . . .  42
   2.2.2  Header field: Content-ID . . . . . . . . . . .  42
   5.     Acknowledgements . . . . . .  43
   2.2.3  Header field: Content-Description  . . . . . . . . . . . .  43
   2.2.4  Header field: Content-Transfer-Encoding  . . . .  42
          References . . . . .  43
   2.2.5  Header field: Content-Type . . . . . . . . . . . . . . . .  44
   2.2.6  Header field: Content-Base . . .  43
          Authors' Addresses . . . . . . . . . . . . .  44
   2.2.7  Header field: Content-Location . . . . . . .  44
   A.     Revision history . . . . . . .  45
   2.2.8  Header field: Content-features . . . . . . . . . . . . . .  45
   A.1    draft-klyne-hdrreg-mail-02
   2.2.9  Header field: Content-Disposition  . . . . . . . . . . . .  46
   2.2.10 Header field: Content-Language . . . .  45
   A.2    draft-klyne-hdrreg-mail-01 . . . . . . . . . .  46
   2.2.11 Header field: Content-Alternative  . . . . . .  45
   A.3    draft-klyne-hdrreg-mail-00 . . . . . .  47
   2.2.12 Header field: Content-MD5  . . . . . . . . . .  46
   B.     TODO: . . . . . .  47
   2.2.13 Header field: Content-Duration . . . . . . . . . . . . . .  48
   3.     IANA considerations  . . . . . .  46
          Intellectual Property and Copyright Statements . . . . . .  47 . . . . . . .  48



Klyne & Palme           Expires August 19, October 12, 2004                [Page 3]

Internet-Draft       Mail/MIME header registration         February            April 2004


1. Introduction

   This document defines IANA registration for a number of mail message
   and MIME header fields, per Registration procedures for message
   header fields [1].

   [[[The main body of this document is automatically generated. Some
   sample HTML registry pages have


   4.     Security considerations  . . . . . . . . . . . . . . . . .  48
   5.     Acknowledgements . . . . . . . . . . . . . . . . . . . . .  48
          Normative references . . . . . . . . . . . . . . . . . . .  49
          Informative references . . . . . . . . . . . . . . . . . .  50
          Authors' Addresses . . . . . . . . . . . . . . . . . . . .  51
   A.     Revision history . . . . . . . . . . . . . . . . . . . . .  51
   A.1    draft-klyne-hdrreg-mail-03 . . . . . . . . . . . . . . . .  51
   A.2    draft-klyne-hdrreg-mail-02 . . . . . . . . . . . . . . . .  52
   A.3    draft-klyne-hdrreg-mail-01 . . . . . . . . . . . . . . . .  52
   A.4    draft-klyne-hdrreg-mail-00 . . . . . . . . . . . . . . . .  53
   B.     TODO:  . . . . . . . . . . . . . . . . . . . . . . . . . .  53
          Intellectual Property and Copyright Statements . . . . . .  54







































Klyne & Palme           Expires October 12, 2004                [Page 4]

Internet-Draft       Mail/MIME header registration            April 2004


1. Introduction

   This document defines IANA registration for a number of mail message
   and MIME header fields, per Registration procedures for message
   header fields [1].

   [[[The main body of this document is automatically generated. Some
   sample HTML registry pages have been prepared from the same data, same data, and
   can be found at  [28].]]]

1.1 Structure of this document

   Section Section 2 contains the submission for initial registration of
   mail related message headers fields.

1.2 Document terminology and conventions

   The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
   "SHOULD", "SHOULD NOT", "RECOMMENDED",  "MAY", and "OPTIONAL" in this
   document are to be interpreted as described in RFC 2119 [10].

      NOTE: indented comments like this provide additional nonessential
      information about the rationale behind this document.

   [[[Editorial comments and questions about outstanding issues are
   provided in triple brackets like this.  These working comments should
   be resolved and removed prior to final publication.]]]

2. Registration templates

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

2.1 Permanent mail header field registrations


   Header name         Protocol
   -----------         --------
   Date                Mail      Message date and time
   From                Mail      Mailbox of message author
   Sender              Mail      Mailbox of message sender
   Reply-To            Mail      Mailbox for replies to message
   To                  Mail      Primary recipient mailbox
   Cc                  Mail      Carbon-copy recipient mailbox
   Bcc                 Mail      Blind-carbon-copy recipient
                                 mailbox
   Message-ID          Mail      Message identifier



Klyne & Palme           Expires October 12, 2004                [Page 5]

Internet-Draft       Mail/MIME header registration            April 2004


   In-Reply-To         Mail      Identify replied-to message(s)
   References          Mail      Related message identifier(s)
   Subject             Mail      Topic of message
   Comments            Mail      Additional comments about the
                                 message
   Keywords            Mail      Message key words and/or phrases
   Resent-Date         Mail      Date and time message is resent
   Resent-From         Mail      Mailbox of person for whom message
                                 is resent
   Resent-Sender       Mail      Mailbox of person who actually
                                 resends the message
   Resent-To           Mail      Mailbox to which message is resent
   Resent-Cc           Mail      Mailbox(es) to which message is
                                 cc'ed on resend
   Resent-Bcc          Mail      Mailbox(es) to which message is
                                 bcc'ed on resend
   Resent-Reply-To     Mail      Resent reply-to
   Resent-Message-ID   Mail      Message identifier for resent
                                 message
   Return-Path         Mail      Message return path
   Received            Mail      Mail transfer trace information
   Disposition-Notification-To
                       Mail      Mailbox for sending disposition
                                 notification
   Disposition-Notification-Options
                       Mail      Disposition notification options
   Accept-Language     Mail      Language(s) for auto-responses
   Original-Message-ID Mail      Original message identifier
   PICS-Label          Mail      PICS rating label
   Encoding            Mail      Message encoding and other
                                 information
   List-Archive        Mail      URL of mailing list archive
   List-Help           Mail      URL for mailing list information
   List-ID             Mail      Mailing list identifier
   List-Owner          Mail      URL for mailing list owner's
                                 mailbox
   List-Post           Mail      URL for mailing list posting
   List-Subscribe      Mail      URL for mailing list subscription
   List-Unsubscribe    Mail      URL for mailing list
                                 unsubscription
   Message-Context     Mail      Type or context of message
   DL-Expansion-History
                       Mail      Trace of distribution lists passed
   Alternate-Recipient Mail      Controls forwarding to alternate
                                 recipients
   Original-Encoded-Information-Types
                       Mail      Body part types in message
   Content-Return      Mail      Return content on non-delivery?



Klyne & Palme           Expires October 12, 2004                [Page 6]

Internet-Draft       Mail/MIME header registration            April 2004


   Generate-Delivery-Report
                       Mail      Request delivery report generation
   Prevent-NonDelivery-Report
                       Mail      Non-delivery report required?
   Obsoletes           Mail      Reference message to be replaced
   Supersedes          Mail      Reference message to be replaced
   Content-Identifier  Mail      Message content identifier
   Delivery-Date       Mail      Message delivery time
   Expiry-Date         Mail      Message expiry time
   Expires             Mail      Message expiry time
   Reply-By            Mail      Time by which a reply is requested
   Importance          Mail      Message importance
   Incomplete-Copy     Mail      Body parts are missing.
   Priority            Mail      Message priority
   Sensitivity         Mail      Message content sensitivity
   Language            Mail      X.400 message content lenguage
   Conversion          Mail      Conversion allowed?
   Conversion-With-Loss
                       Mail      Lossy conversion allowed?
   Message-Type        Mail      Message type: delivery report?
   Autosubmitted       Mail      Automatically submitted indicator
   Autoforwarded       Mail      Automatically forwarded indicator
   Discarded-X400-IPMS-Extensions
                       Mail      X.400 IPM extensions discarded
   Discarded-X400-MTS-Extensions
                       Mail      X.400 MTS extensions discarded
   Disclose-Recipients Mail      Disclose names of other
                                 recipients?
   Deferred-Delivery   Mail      Deferred delivery information
   Latest-Delivery-Time
                       Mail      Latest delivery time requested
   Originator-Return-Address
                       Mail      Originator return address
   X400-Content-Identifier
                       Mail      Message content identifier
   X400-Content-Return Mail      Return content on non-delivery?
   X400-Content-Type   Mail      X400 content type
   X400-MTS-Identifier Mail      X400 MTS-Identifier
   X400-Originator     Mail      X400 Originator
   X400-Received       Mail      X400 Received
   X400-Recipients     Mail      X400 Recipients
   X400-Trace          Mail      X400 Trace

               Figure 1: MailHeaderPermanentRegistry.xml







Klyne & Palme           Expires October 12, 2004                [Page 7]

Internet-Draft       Mail/MIME header registration            April 2004


2.1.1 Header field: Date

   Description:
      Message date and time

   Applicable protocol: Mail [19]

   Status: standards-track

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

   Specification document(s):
      RFC 2822 [19] (section 3.6.1)

   Related information:
      Specifies the date and
   can be found time at  [21].]]]

1.1 Structure of this document

   Section Section 2 contains which the submission for initial registration creator of
   mail related the message headers fields.

1.2 Document terminology and conventions

   The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
   "SHOULD", "SHOULD NOT", "RECOMMENDED",  "MAY", and "OPTIONAL" in this
   document are to be interpreted as described in RFC 2119 [10].

      NOTE: indented comments like this provide additional nonessential
      information about
      indicated that the rationale behind this document.

   [[[Editorial comments and questions about outstanding issues are
   provided in triple brackets like this.  These working comments should
   be resolved message was complete and removed prior ready to final publication.]]]

2. Registration templates

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

2.1 Permanent
      mail header field registrations delivery system.


2.1.2 Header name         Protocol
   -----------         --------
   Date                Mail      Message date and time field: From                Mail

   Description:
      Mailbox of message author
   Sender

   Applicable protocol: Mail      Mailbox [19]

   Status: standards-track

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

   Specification document(s):
      RFC 2822 [19] (section 3.6.2)

   Related information:
      Specifies the author(s) of message sender
   Reply-To            Mail      Mailbox the message, that is, the mailbox(es)
      of the person(s) or system(s) responsible for replies to message
   To                  Mail      Primary recipient mailbox
   Cc                  Mail      Carbon-copy recipient mailbox
   Bcc                 Mail      Blind-carbon-copy recipient
                                 mailbox
   Message-ID          Mail      Message identifier the writing of the
      message.


2.1.3 Header field: Sender






Klyne & Palme           Expires August 19, October 12, 2004                [Page 4] 8]

Internet-Draft       Mail/MIME header registration         February            April 2004


   In-Reply-To         Mail      Original message identifier(s)
   References          Mail      Related message identifier(s)
   Subject             Mail      Topic of message
   Comments            Mail      Additional comments about the
                                 message
   Keywords            Mail      Message key words and/or phrases
   Resent-Date         Mail      Date and time message is resent
   Resent-From         Mail      Mailbox of person for whom message
                                 is resent
   Resent-Sender       Mail


   Description:
      Mailbox of person who actually
                                 resends the message
   Resent-To           Mail      Mailbox to which message is resent
   Resent-Cc           Mail      Mailbox(es) to which message is
                                 cc'ed on resend
   Resent-Bcc          Mail      Mailbox(es) to which message is
                                 bcc'ed on resend
   Resent-Message-ID   Mail      Message identifier for resent message
   Return-Path         Mail      Message return path
   Received            Mail      Mail transfer trace information
   Disposition-Notification-To
                       Mail      Mailbox for sending disposition
                                 notification
   Disposition-Notification-Options
                       Mail      Disposition notification options
   Original-Recipient  Mail      MDN original recipient information
   Originator          Mail      Similar to 'Sender:'
   PICS-Label          Mail      PICS rating label
   Encoding            Mail      Message encoding and other
                                 information
   List-Archive        Mail      URL of mailing list archive
   List-Help           Mail      URL for mailing list information
   List-ID             Mail      Mailing list identifier
   List-Owner sender

   Applicable protocol: Mail      URL for mailing list owner's [19]

   Status: standards-track

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

   Specification document(s):
      RFC 2822 [19] (section 3.6.2)

   Related information:
      Specifies the mailbox
   List-Post           Mail      URL for mailing list posting
   List-Subscribe      Mail      URL of the agent responsible for mailing list subscription
   List-Unsubscribe    Mail      URL the actual
      transmission of the message.


2.1.4 Header field: Reply-To

   Description:
      Mailbox for mailing list
                                 unsubscription
   Message-Context replies to message

   Applicable protocol: Mail      Type or context [19]

   Status: standards-track

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

   Specification document(s):
      RFC 2822 [19] (section 3.6.2)

   Related information:
      When the "Reply-To:" field is present, it indicates the
      mailbox(es) to which the author of the message
   DL-Expansion-History suggests that
      replies be sent.


2.1.5 Header field: To

   Description:
      Primary recipient mailbox






Klyne & Palme           Expires October 12, 2004                [Page 9]

Internet-Draft       Mail/MIME header registration            April 2004


   Applicable protocol: Mail      Trace [19]

   Status: standards-track

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

   Specification document(s):
      RFC 2822 [19] (section 3.6.3)

   Related information:
      Contains the address(es) of distribution lists passed
   Alternate-Recipient the primary recipient(s) of the
      message.


2.1.6 Header field: Cc

   Description:
      Carbon-copy recipient mailbox

   Applicable protocol: Mail      Controls forwarding [19]

   Status: standards-track

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

   Specification document(s):
      RFC 2822 [19] (section 3.6.3)

   Related information:
      Contains the addresses of others who are to alternate
                                 recipients
   Original-Encoded-Information-Types
                       Mail      Body part types in receive the message,
      though the content of the message
   Content-Return may not be directed at them.


2.1.7 Header field: Bcc

   Description:
      Blind-carbon-copy recipient mailbox

   Applicable protocol: Mail      Return content on non-delivery?
   Generate-Delivery-Report [19]

   Status: standards-track






Klyne & Palme           Expires August 19, October 12, 2004               [Page 5] 10]

Internet-Draft       Mail/MIME header registration         February            April 2004


                       Mail      Request delivery report generation
   Prevent-NonDelivery-Report
                       Mail      Non-delivery report required?
   Obsoletes           Mail      Reference


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

   Specification document(s):
      RFC 2822 [19] (section 3.6.3)

   Related information:
      Contains addresses of recipients of the message whose addresses
      are not to be replaced
   Content-Identifier  Mail revealed to other recipients of the message.


2.1.8 Header field: Message-ID

   Description:
      Message content identifier
   Delivery-Date       Mail      Message delivery time
   Expiry-Date         Mail      Message expiry time
   Reply-By

   Applicable protocol: Mail      Time by which [19]

   Status: standards-track

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

   Specification document(s):
      RFC 2822 [19] (section 3.6.4)

   Related information:
      Contains a reply is requested
   Importance          Mail      Message importance
   Incomplete-Copy     Mail      Body parts are missing.
   Priority            Mail      Message priority
   Sensitivity         Mail      Message content sensitivity
   Language            Mail      X.400 single unique message content lenguage
   Conversion          Mail      Conversion allowed?
   Conversion-With-Loss
                       Mail      Lossy conversion allowed?
   Message-Type        Mail      Message type: delivery report?
   Autoforwarded       Mail      Automatically forwarded indicator
   Discarded-X400-IPMS-Extensions
                       Mail      X.400 IPM extensions discarded
   Discarded-X400-MTS-Extensions
                       Mail      X.400 MTS extensions discarded
   Disclose-Recipients Mail      Disclose names identifier that refers to a
      particular version of other
                                 recipients?

                                Figure 1


2.1.1 a particular message. If the message is
      resent without changes, the original Message-ID is retained.


2.1.9 Header field: Date In-Reply-To

   Description:
      Message date and time
      Identify replied-to message(s)

   Applicable protocol: Mail (http://www.rfc-editor.org/rfc/rfc2822.txt) [19]

   Status: standards-track

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

   Specification document(s):
      http://www.rfc-editor.org/rfc/rfc2822.txt (section 3.6.1) Force





Klyne & Palme           Expires August 19, October 12, 2004               [Page 6] 11]

Internet-Draft       Mail/MIME header registration         February            April 2004


   Specification document(s):
      RFC 2822 [19] (section 3.6.4)

   Related information:
      Specifies the date and time at which the creator of the
      The message
      indicated that identifier(s) of the message was complete and ready original message(s) to enter which the
      mail delivery system.


2.1.2
      current message is a reply.


2.1.10 Header field: From References

   Description:
      Mailbox of
      Related message author identifier(s)

   Applicable protocol: Mail (http://www.rfc-editor.org/rfc/rfc2822.txt) [19]

   Status: standards-track

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

   Specification document(s):
      http://www.rfc-editor.org/rfc/rfc2822.txt
      RFC 2822 [19] (section 3.6.2) 3.6.4)

   Related information:
      Specifies the author(s)
      The message identifier(s) of other message(s) to which the message, current
      message may be related. In RFC2822, the definition was changed to
      say that is, the mailbox(es) this header field contains a list of the person(s) or system(s) responsible for the writing all Message-IDs of
      messages in the
      message.


2.1.3 preceding reply chain.


2.1.11 Header field: Sender Subject

   Description:
      Mailbox
      Topic of message sender

   Applicable protocol: Mail (http://www.rfc-editor.org/rfc/rfc2822.txt) [19]

   Status: standards-track

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

   Specification document(s):
      http://www.rfc-editor.org/rfc/rfc2822.txt
      RFC 2822 [19] (section 3.6.2) 3.6.5)





Klyne & Palme           Expires August 19, October 12, 2004               [Page 7] 12]

Internet-Draft       Mail/MIME header registration         February            April 2004


   Related information:
      Specifies the mailbox of the agent responsible for
      Contains a short string identifying the actual
      transmission topic of the message.


2.1.4


2.1.12 Header field: Reply-To Comments

   Description:
      Mailbox for replies to
      Additional comments about the message

   Applicable protocol: Mail (http://www.rfc-editor.org/rfc/rfc2822.txt) [19]

   Status: standards-track

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

   Specification document(s):
      http://www.rfc-editor.org/rfc/rfc2822.txt
      RFC 2822 [19] (section 3.6.2) 3.6.5)

   Related information:
      When the "Reply-To:" field is present, it indicates
      Contains any additional comments on the
      mailbox(es) to which text of the author body of the message suggests that
      replies be sent.


2.1.5
      message. Warning: Some mailers will not show this field to
      recipients.


2.1.13 Header field: To Keywords

   Description:
      Primary recipient mailbox
      Message key words and/or phrases

   Applicable protocol: Mail (http://www.rfc-editor.org/rfc/rfc2822.txt) [19]

   Status: standards-track

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

   Specification document(s):
      http://www.rfc-editor.org/rfc/rfc2822.txt
      RFC 2822 [19] (section 3.6.3) 3.6.5)

   Related information:
      Contains a comma-separated list of important words and phrases
      that might be useful for the recipient.






Klyne & Palme           Expires August 19, October 12, 2004               [Page 8] 13]

Internet-Draft       Mail/MIME header registration         February            April 2004


2.1.14 Header field: Resent-Date

   Description:
      Date and time message is resent

   Applicable protocol: Mail [19]

   Status: standards-track

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

   Specification document(s):
      RFC 2822 [19] (section 3.6.6)

   Related information:
      Contains the address(es) of the primary recipient(s) of date and time that a message is reintroduced into the
      message.


2.1.6
      message transfer system.


2.1.15 Header field: Cc Resent-From

   Description:
      Carbon-copy recipient mailbox
      Mailbox of person for whom message is resent

   Applicable protocol: Mail (http://www.rfc-editor.org/rfc/rfc2822.txt) [19]

   Status: standards-track

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

   Specification document(s):
      http://www.rfc-editor.org/rfc/rfc2822.txt
      RFC 2822 [19] (section 3.6.3) 3.6.6)

   Related information:
      Contains the addresses mailbox of others who are to receive the message,
      though agent who has reintroduced the content of message
      into the message may not be directed at them.


2.1.7 transfer system, or on whose behanlf the message
      has been resent.


2.1.16 Header field: Bcc Resent-Sender

   Description:
      Blind-carbon-copy recipient mailbox
      Mailbox of person who actually resends the message




Klyne & Palme           Expires October 12, 2004               [Page 14]

Internet-Draft       Mail/MIME header registration            April 2004


   Applicable protocol: Mail (http://www.rfc-editor.org/rfc/rfc2822.txt) [19]

   Status: standards-track

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

   Specification document(s):
      http://www.rfc-editor.org/rfc/rfc2822.txt
      RFC 2822 [19] (section 3.6.3)






Klyne & Palme           Expires August 19, 2004                 [Page 9]

Internet-Draft       Mail/MIME header registration         February 2004 3.6.6)

   Related information:
      Contains addresses of recipients the mailbox of the agent who has reintroduced the message whose addresses
      are not to be revealed to other recipients of
      into the message.


2.1.8 message transfer system, if this is different from the
      Resent-from value.


2.1.17 Header field: Message-ID Resent-To

   Description:
      Message identifier
      Mailbox to which message is resent

   Applicable protocol: Mail (http://www.rfc-editor.org/rfc/rfc2822.txt) [19]

   Status: standards-track

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

   Specification document(s):
      http://www.rfc-editor.org/rfc/rfc2822.txt
      RFC 2822 [19] (section 3.6.4) 3.6.6)

   Related information:
      Contains a single unique message identifier that refers the mailbox(es) to a
      particular version of a particular message. If which the message is
      resent without changes, the original Message-ID is retained.


2.1.9 has been resent.


2.1.18 Header field: In-Reply-To Resent-Cc

   Description:
      Original
      Mailbox(es) to which message identifier(s) is cc'ed on resend

   Applicable protocol: Mail (http://www.rfc-editor.org/rfc/rfc2822.txt) [19]

   Status: standards-track

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

   Specification document(s):
      http://www.rfc-editor.org/rfc/rfc2822.txt (section 3.6.4)






Klyne & Palme           Expires August 19, October 12, 2004               [Page 10] 15]

Internet-Draft       Mail/MIME header registration         February            April 2004


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

   Specification document(s):
      RFC 2822 [19] (section 3.6.6)

   Related information:
      The message identifier(s) of
      Containes the original message(s) mailbox(es) to which the
      current message is a reply.


2.1.10 cc'ed on resend


2.1.19 Header field: References Resent-Bcc

   Description:
      Related
      Mailbox(es) to which message identifier(s) is bcc'ed on resend

   Applicable protocol: Mail (http://www.rfc-editor.org/rfc/rfc2822.txt) [19]

   Status: standards-track

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

   Specification document(s):
      http://www.rfc-editor.org/rfc/rfc2822.txt
      RFC 2822 [19] (section 3.6.4) 3.6.6)

   Related information:
      The message identifier(s) of other message(s)
      Containes the mailbox(es) to which the current message may be related. In RFC2822, the definition was changed to
      say that this header field contains a list of all Message-IDs of
      messages in the preceding reply chain.


2.1.11 is bcc'ed on resend


2.1.20 Header field: Subject Resent-Reply-To

   Description:
      Topic of message
      Resent reply-to

   Applicable protocol: Mail (http://www.rfc-editor.org/rfc/rfc2822.txt) [19]

   Status:
      standards-track obsolete

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

   Specification document(s):
      http://www.rfc-editor.org/rfc/rfc2822.txt (section 3.6.5)
      RFC 2822 [19]





Klyne & Palme           Expires August 19, October 12, 2004               [Page 11] 16]

Internet-Draft       Mail/MIME header registration         February            April 2004


   Related information:
      Contains a short string identifying the topic of the message.


2.1.12
      Resent Reply-to.  Defined by RFC 822, obsoleteed by RFC2822.


2.1.21 Header field: Comments Resent-Message-ID

   Description:
      Additional comments about the
      Message identifier for resent message

   Applicable protocol: Mail (http://www.rfc-editor.org/rfc/rfc2822.txt) [19]

   Status: standards-track

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

   Specification document(s):
      http://www.rfc-editor.org/rfc/rfc2822.txt
      RFC 2822 [19] (section 3.6.5) 3.6.6)

   Related information:
      Contains any additional comments on the text of the body of the
      message. Warning: Some mailers will not show this field to
      recipients.


2.1.13 a message identifier for a resent message


2.1.22 Header field: Keywords Return-Path

   Description:
      Message key words and/or phrases return path

   Applicable protocol: Mail (http://www.rfc-editor.org/rfc/rfc2822.txt) [19]

   Status: standards-track

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

   Specification document(s):
      http://www.rfc-editor.org/rfc/rfc2822.txt
      RFC 2822 [19] (section 3.6.5) 3.6.7)

   Related information:
      Return path for message response diagnostics. See also, RFC 2821.


2.1.23 Header field: Received






Klyne & Palme           Expires August 19, October 12, 2004               [Page 12] 17]

Internet-Draft       Mail/MIME header registration         February            April 2004


   Related information:
      Contains a comma-separated list of important words and phrases
      that might be useful for the recipient.


2.1.14 Header field: Resent-Date


   Description:
      Date and time message is resent
      Mail transfer trace information

   Applicable protocol: Mail (http://www.rfc-editor.org/rfc/rfc2822.txt) [19]

   Status: standards-track

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

   Specification document(s):
      http://www.rfc-editor.org/rfc/rfc2822.txt
      RFC 2822 [19] (section 3.6.6) 3.6.7)

   Related information:
      Contains information about receipt of the date and time that a current message is reintroduced into by a
      mail transfer agent on the
      message transfer system.


2.1.15 path. See also, RFC 2821.


2.1.24 Header field: Resent-From Disposition-Notification-To

   Description:
      Mailbox of person for whom message is resent sending disposition notification

   Applicable protocol: Mail (http://www.rfc-editor.org/rfc/rfc2822.txt) [19]

   Status: standards-track

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

   Specification document(s):
      http://www.rfc-editor.org/rfc/rfc2822.txt (section 3.6.6)






Klyne & Palme           Expires August 19, 2004                [Page 13]

Internet-Draft       Mail/MIME header registration         February 2004
      RFC 2298 [13]

   Related information:
      Contains the mailbox of the agent who has reintroduced the message
      into the message transfer system, or on whose behanlf
      Indicates that the sender wants a disposition notification when
      this message
      has been resent.


2.1.16 is received (read, processed, etc.) by its
      recipients.


2.1.25 Header field: Resent-Sender Disposition-Notification-Options

   Description:
      Mailbox of person who actually resends the message
      Disposition notification options






Klyne & Palme           Expires October 12, 2004               [Page 18]

Internet-Draft       Mail/MIME header registration            April 2004


   Applicable protocol: Mail (http://www.rfc-editor.org/rfc/rfc2822.txt) [19]

   Status: standards-track

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

   Specification document(s):
      http://www.rfc-editor.org/rfc/rfc2822.txt (section 3.6.6)
      RFC 2298 [13]

   Related information:
      Contains the mailbox of the agent who has reintroduced the message
      into the message transfer system, if this is different from the
      Resent-from value.


2.1.17
      For optional modifiers on disposition notification requests.


2.1.26 Header field: Resent-To Accept-Language

   Description:
      Mailbox to which message is resent
      Language(s) for auto-responses

   Applicable protocol: Mail (http://www.rfc-editor.org/rfc/rfc2822.txt) [19]

   Status: standards-track

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

   Specification document(s):
      http://www.rfc-editor.org/rfc/rfc2822.txt (section 3.6.6)
      RFC 3282 [22]

   Related information:
      Indicates a language that the message sender requests be used for
      responses. Accept-language was not designed for email, but has
      been considered to be useful as input to the generation of
      automatic replies. Some problems have been noted concerning its
      use with email, including but not limited to: determination of the
      email address to which it refers; cost and lack of effective
      internationalization of email responses; interpretation of
      language subtags; determining what character set encoding should
      be used.


2.1.27 Header field: Original-Message-ID

   Description:
      Original message identifier




Klyne & Palme           Expires August 19, October 12, 2004               [Page 14] 19]

Internet-Draft       Mail/MIME header registration         February            April 2004


   Related information:
      Contains the mailbox(es) to which the message has been resent.


2.1.18 Header field: Resent-Cc

   Description:
      Mailbox(es) to which message is cc'ed on resend


   Applicable protocol: Mail (http://www.rfc-editor.org/rfc/rfc2822.txt) [19]

   Status: standards-track

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

   Specification document(s):
      http://www.rfc-editor.org/rfc/rfc2822.txt (section 3.6.6)
      RFC 3297 [23]

   Related information:
      Containes
      Original message identifier used with resend of message with
      alternative content format, identifies the mailbox(es) original message data
      to which message is cc'ed on resend


2.1.19 it corresponds.


2.1.28 Header field: Resent-Bcc PICS-Label

   Description:
      Mailbox(es) to which message is bcc'ed on resend
      PICS rating label

   Applicable protocol: Mail (http://www.rfc-editor.org/rfc/rfc2822.txt) [19]

   Status:
      standards-track standard

   Author/change controller:
      IETF  (mailto:iesg@ietf.org)
      Internet Engineering Task Force.
      W3C  (mailto:web-human@w3.org)
      World Wide Web Consortium

   Specification document(s):
      http://www.rfc-editor.org/rfc/rfc2822.txt (section 3.6.6)
      http://www.w3.org/TR/REC-PICS-labels [25]

   Related information:
      Containes the mailbox(es)
      Ratings label to which message is bcc'ed on resend control selection (filtering) of messages
      according to the PICS protocol.  Specified for general use with
      RFC822 message format, with HTTP-specific extensions


2.1.29 Header field: Encoding

   Description:
      Message encoding and other information

   Applicable protocol: Mail [19]






Klyne & Palme           Expires August 19, October 12, 2004               [Page 15] 20]

Internet-Draft       Mail/MIME header registration         February            April 2004


2.1.20 Header field: Resent-Message-ID

   Description:
      Message identifier for resent message

   Applicable protocol:
      Mail (http://www.rfc-editor.org/rfc/rfc2822.txt)


   Status:
      standards-track experimental

   Author/change controller:
      IETF  (mailto:iesg@ietf.org)
      Internet Engineering Task Force.
      Albert K. Costanzo  (mailto:AL@AKC.COM)
      AKC Consulting Inc.

   Specification document(s):
      http://www.rfc-editor.org/rfc/rfc2822.txt (section 3.6.6)
      RFC 1505 [4]

   Related information:
      Contains
      Used in several different ways by different mail systems. Some use
      it for a message identifier kind of content-type information, some for encoding and
      length information, some for a resent message


2.1.21 kind of boundary information, some
      in other ways.


2.1.30 Header field: Return-Path List-Archive

   Description:
      Message return path
      URL of mailing list archive

   Applicable protocol: Mail (http://www.rfc-editor.org/rfc/rfc2822.txt) [19]

   Status: standards-track

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

   Specification document(s):
      http://www.rfc-editor.org/rfc/rfc2822.txt (section 3.6.7)
      RFC 2369 [14]

   Related information:
      Return path for
      Contains URL to use to browse the archives of the mailing list
      from which this message response diagnostics. See also, RFC 2821.


2.1.22 was relayed.


2.1.31 Header field: Received List-Help

   Description:
      URL for mailing list information

   Applicable protocol: Mail [19]

   Status: standards-track






Klyne & Palme           Expires August 19, October 12, 2004               [Page 16] 21]

Internet-Draft       Mail/MIME header registration         February            April 2004


   Description:
      Mail transfer trace information

   Applicable protocol:
      Mail (http://www.rfc-editor.org/rfc/rfc2822.txt)

   Status:
      standards-track


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

   Specification document(s):
      http://www.rfc-editor.org/rfc/rfc2822.txt (section 3.6.7)
      RFC 2369 [14]

   Related information:
      Contains URL to use to get a information about receipt of the current mailing list
      from which this message by a
      mail transfer agent on the transfer path. See also, RFC 2821.


2.1.23 was relayed.


2.1.32 Header field: Disposition-Notification-To List-ID

   Description:
      Mailbox for sending disposition notification
      Mailing list identifier

   Applicable protocol: Mail (http://www.rfc-editor.org/rfc/rfc2822.txt) [19]

   Status: standards-track

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

   Specification document(s):
      http://www.rfc-editor.org/rfc/rfc2298.txt
      RFC 2919 [21]

   Related information:
      Indicates that
      Stores an identification of the sender wants a disposition notification when mailing list, through which this
      message is received (read, processed, etc.) by its
      recipients.


2.1.24 was distributed.


2.1.33 Header field: Disposition-Notification-Options List-Owner

   Description:
      URL for mailing list owner's mailbox

   Applicable protocol: Mail [19]

   Status: standards-track

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






Klyne & Palme           Expires August 19, October 12, 2004               [Page 17] 22]

Internet-Draft       Mail/MIME header registration         February            April 2004


   Specification document(s):
      RFC 2369 [14]

   Related information:
      Contains URL to send e-mail to the owner of the mailing list from
      which this message was relayed.


2.1.34 Header field: List-Post

   Description:
      Disposition notification options
      URL for mailing list posting

   Applicable protocol: Mail (http://www.rfc-editor.org/rfc/rfc2822.txt) [19]

   Status: standards-track

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

   Specification document(s):
      http://www.rfc-editor.org/rfc/rfc2298.txt
      RFC 2369 [14]

   Related information:
      For optional modifiers on disposition notification requests.


2.1.25
      Contains URL to use to send contributions to the mailing list from
      which this message was relayed.


2.1.35 Header field: Original-Recipient List-Subscribe

   Description:
      MDN original recipient information
      URL for mailing list subscription

   Applicable protocol: Mail (http://www.rfc-editor.org/rfc/rfc2822.txt) [19]

   Status: standards-track

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

   Specification document(s):
      http://www.rfc-editor.org/rfc/rfc2298.txt
      RFC 2369 [14]

   Related information:
      Original Recipient information for inclusion in disposition
      notifications.


2.1.26 Header field: Originator

   Description:
      Similar
      Contains URL to use to get a subscription to 'Sender:' the mailing list from
      which this message was relayed.



Klyne & Palme           Expires August 19, October 12, 2004               [Page 18] 23]

Internet-Draft       Mail/MIME header registration         February            April 2004


2.1.36 Header field: List-Unsubscribe

   Description:
      URL for mailing list unsubscription

   Applicable protocol: Mail (http://www.rfc-editor.org/rfc/rfc2822.txt) [19]

   Status:
      experimental standards-track

   Author/change controller:
      Carl Malamud  (mailto:carl@malamud.com)
      IETF  (mailto:iesg@ietf.org)
      Internet Multicasting Service. Engineering Task Force

   Specification document(s):
      http://www.rfc-editor.org/rfc/rfc1528.txt
      RFC 2369 [14]

   Related information:
      Sometimes used in Usenet News in similar ways
      Contains URL to 'Sender:' Also
      used in printing protocols. Non-standard in Usenet News,
      Experimental in RFC 1528 (tcp.int).


2.1.27 use to unsubscribe the mailing list from which
      this message was relayed.


2.1.37 Header field: PICS-Label Message-Context

   Description:
      PICS rating label
      Type or context of message

   Applicable protocol: Mail (http://www.rfc-editor.org/rfc/rfc2822.txt) [19]

   Status:
      standard Standards track

   Author/change controller:
      W3C  (mailto:web-human@w3.org)
      World Wide Web Consortium.
      IETF  (mailto:iesg@ietf.org)
      Internet Engineering Task Force

   Specification document(s):
      http://www.w3.org/TR/REC-PICS-labels
      RFC3458 [24]

   Related information:
      Ratings label to control selection (filtering)
      Provides information about the context and presentation
      characteristics of messages
      according to a message.  Can have the PICS protocol.  Specified for general use with
      RFC822 message format, with HTTP-specific extensions


2.1.28 values
      'voice-message', 'fax-message', 'pager-message',
      'multimedia-message', 'text-message', 'none'.


2.1.38 Header field: Encoding

   Description:
      Message encoding and other information field: DL-Expansion-History






Klyne & Palme           Expires August 19, October 12, 2004               [Page 19] 24]

Internet-Draft       Mail/MIME header registration         February            April 2004


   Description:
      Trace of distribution lists passed

   Applicable protocol: Mail (http://www.rfc-editor.org/rfc/rfc2822.txt) [19]

   Status:
      experimental standards-track

   Author/change controller:
      Albert K. Costanzo  (mailto:AL@AKC.COM)
      AKC Consulting Inc..
      IETF  (mailto:iesg@ietf.org)
      Internet Engineering Task Force

   Specification document(s):
      http://www.rfc-editor.org/rfc/rfc1505.txt
      RFC 2156 [11]

   Related information:
      Used in several different ways by different mail systems. Some use
      it for a kind
      Trace of content-type information, some for encoding and
      length information, some distribution lists passed. (MIXER X.400 mapping, not for a kind of boundary information, some
      in other ways.


2.1.29
      general use.)


2.1.39 Header field: List-Archive Alternate-Recipient

   Description:
      URL of mailing list archive
      Controls forwarding to alternate recipients

   Applicable protocol: Mail (http://www.rfc-editor.org/rfc/rfc2822.txt) [19]

   Status: standards-track

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

   Specification document(s):
      http://www.rfc-editor.org/rfc/rfc2369.txt
      RFC 2156 [11]

   Related information:
      Contains URL
      Controls whether this message may be forwarded to use alternate
      recipients such as a postmaster if delivery is not possible to browse the archives of the mailing list
      from which this message was relayed.


2.1.30
      intended recipient. Default: Allowed. RFC 2156 (MIXER), not for
      general use.


2.1.40 Header field: List-Help Original-Encoded-Information-Types

   Description:
      URL for mailing list information
      Body part types in message





Klyne & Palme           Expires August 19, October 12, 2004               [Page 20] 25]

Internet-Draft       Mail/MIME header registration         February            April 2004


   Applicable protocol: Mail (http://www.rfc-editor.org/rfc/rfc2822.txt) [19]

   Status: standards-track

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

   Specification document(s):
      http://www.rfc-editor.org/rfc/rfc2369.txt
      RFC 2156 [11]

   Related information:
      Contains URL to use to get a information about the mailing list
      from which
      Which body part types occur in this message was relayed.


2.1.31 message. RFC 2156 (MIXER), not
      for general use.


2.1.41 Header field: List-ID Content-Return

   Description:
      Mailing list identifier
      Return content on non-delivery?

   Applicable protocol: Mail (http://www.rfc-editor.org/rfc/rfc2822.txt) [19]

   Status:
      standards-track obsolete

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

   Specification document(s):
      http://www.rfc-editor.org/rfc/rfc1919.txt
      RFC 1327 [2]

   Related information:
      Stores an identification of
      Indicates whether the mailing list, through which this content of a message was distributed.


2.1.32 is to be returned with
      non-delivery notifications. Introduced by RFC 1327, and
      subsequently changed by RFC 2156 to avoid confusion with MIME
      defined fields.


2.1.42 Header field: List-Owner Generate-Delivery-Report

   Description:
      URL for mailing list owner's mailbox
      Request delivery report generation

   Applicable protocol: Mail [19]






Klyne & Palme           Expires August 19, October 12, 2004               [Page 21] 26]

Internet-Draft       Mail/MIME header registration         February            April 2004


   Applicable protocol:
      Mail (http://www.rfc-editor.org/rfc/rfc2822.txt)


   Status: standards-track

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

   Specification document(s):
      http://www.rfc-editor.org/rfc/rfc2369.txt
      RFC 2156 [11]

   Related information:
      Contains URL to send e-mail
      Indicates whether a delivery report is wanted at successful
      delivery. Default is not to the owner of the mailing list from
      which this message was relayed.


2.1.33 generate such a report. RFC 2156
      (MIXER), not for general use.


2.1.43 Header field: List-Post Prevent-NonDelivery-Report

   Description:
      URL for mailing list posting
      Non-delivery report required?

   Applicable protocol: Mail (http://www.rfc-editor.org/rfc/rfc2822.txt) [19]

   Status: standards-track

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

   Specification document(s):
      http://www.rfc-editor.org/rfc/rfc2369.txt
      RFC 2156 [11]

   Related information:
      Contains URL to use to send contributions
      Indicates whether non-delivery report is wanted on delivery error.
      Default is to the mailing list from
      which this message was relayed.


2.1.34 generate such a report. RFC 2156 (MIXER), not for
      general use.


2.1.44 Header field: List-Subscribe Obsoletes

   Description:
      URL for mailing list subscription
      Reference message to be replaced

   Applicable protocol: Mail [19]

   Status: obsolete






Klyne & Palme           Expires August 19, October 12, 2004               [Page 22] 27]

Internet-Draft       Mail/MIME header registration         February            April 2004


   Applicable protocol:
      Mail (http://www.rfc-editor.org/rfc/rfc2822.txt)

   Status:
      standards-track


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

   Specification document(s):
      http://www.rfc-editor.org/rfc/rfc2369.txt
      RFC 1327 [2]

   Related information:
      Contains URL to use
      Reference to get a subscription to the mailing list from
      which this previous message was relayed.


2.1.35 being corrected and replaced.
      Compare to 'Supersedes:' used in Usenet News. Introduced by RFC
      1327, and subsequently renamed by RFC 2156 to 'Supersedes'.


2.1.45 Header field: List-Unsubscribe Supersedes

   Description:
      URL for mailing list unsubscription
      Reference message to be replaced

   Applicable protocol: Mail (http://www.rfc-editor.org/rfc/rfc2822.txt) [19]

   Status: standards-track

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

   Specification document(s):
      http://www.rfc-editor.org/rfc/rfc2369.txt
      RFC 2156 [11]

   Related information:
      Contains URL to use
      Reference to unsubscribe the mailing list from which
      this a previous message was relayed.


2.1.36 Header field: Message-Context

   Description:
      Type or context being corrected and replaced.
      Renamed version of message






Klyne & Palme           Expires August 19, 2004                [Page 23]

Internet-Draft       Mail/MIME obsolete 'Obsoletes' header registration         February 2004 field. RFC 2156
      (MIXER), not for general use.


2.1.46 Header field: Content-Identifier

   Description:
      Message content identifier

   Applicable protocol: Mail (http://www.rfc-editor.org/rfc/rfc2822.txt) [19]

   Status:
      Standards track obsolete

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




Klyne & Palme           Expires October 12, 2004               [Page 28]

Internet-Draft       Mail/MIME header registration            April 2004


   Specification document(s):
      http://www.rfc-editor.org/rfc/rfc3458.txt
      RFC 1327 [2]

   Related information:
      Provides information about
      A text string which identifies the context and presentation
      characteristics content of a message.  Can have
      Introduced by RFC 1327, and subsequently changed by RFC 2156 to
      avoid confusion with MIME defined fields. Gateways which reverse
      map may support the values
      'voice-message', 'fax-message', 'pager-message',
      'multimedia-message', 'text-message', 'none'.


2.1.37 old field.


2.1.47 Header field: DL-Expansion-History Delivery-Date

   Description:
      Trace of distribution lists passed
      Message delivery time

   Applicable protocol: Mail (http://www.rfc-editor.org/rfc/rfc2822.txt) [19]

   Status: standards-track

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

   Specification document(s):
      http://www.rfc-editor.org/rfc/rfc2156.txt
      RFC 2156 [11]

   Related information:
      Trace of distribution lists passed. (MIXER X.400 mapping,
      The time when a message was delivered to its recipient. RFC 2156
      (MIXER), not for general use.)


2.1.38 use.


2.1.48 Header field: Alternate-Recipient Expiry-Date

   Description:
      Controls forwarding to alternate recipients
      Message expiry time

   Applicable protocol: Mail [19]

   Status: obsolete

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

   Specification document(s):
      RFC 1327 [2]





Klyne & Palme           Expires August 19, October 12, 2004               [Page 24] 29]

Internet-Draft       Mail/MIME header registration         February            April 2004


   Related information:
      Time at which a message loses its validity. Introduced by RFC
      1327, and subsequently changed by RFC 2156 to 'Expires:'.


2.1.49 Header field: Expires

   Description:
      Message expiry time

   Applicable protocol: Mail (http://www.rfc-editor.org/rfc/rfc2822.txt) [19]

   Status: standards-track

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

   Specification document(s):
      http://www.rfc-editor.org/rfc/rfc2156.txt
      RFC 2156 [11]

   Related information:
      Controls whether this message may be forwarded to alternate
      recipients such as
      Time at which a postmaster if delivery is not possible to the
      intended recipient. Default: Allowed. message loses its validity. Renamed version of
      obsolete Expiry-Date header field. RFC 2156 (MIXER), not for
      general usage.


2.1.39 use.


2.1.50 Header field: Original-Encoded-Information-Types Reply-By

   Description:
      Body part types in message
      Time by which a reply is requested

   Applicable protocol: Mail (http://www.rfc-editor.org/rfc/rfc2822.txt) [19]

   Status: standards-track

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

   Specification document(s):
      http://www.rfc-editor.org/rfc/rfc2156.txt
      RFC 2156 [11]

   Related information:
      Which body part types occur in this message.
      Latest time at which a reply is requested (not demanded). RFC 2156
      (MIXER), not for general use.


2.1.40 Header field: Content-Return

   Description:
      Return content on non-delivery? general use.





Klyne & Palme           Expires August 19, October 12, 2004               [Page 25] 30]

Internet-Draft       Mail/MIME header registration         February            April 2004


2.1.51 Header field: Importance

   Description:
      Message importance

   Applicable protocol: Mail (http://www.rfc-editor.org/rfc/rfc2822.txt) [19]

   Status: standards-track

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

   Specification document(s):
      http://www.rfc-editor.org/rfc/rfc2156.txt
      RFC 2156 [11]

   Related information:
      Indicates whether
      A hint from the content of originator to the recipients about how important a
      message is is.  Values: High, normal or low. Not used to be returned control
      transmission speed. Proposed for use with
      non-delivery notifications. RFC 2156 (MIXER), not for general use.


2.1.41 (MIXER) and RFC
      2421 (VPIM).


2.1.52 Header field: Generate-Delivery-Report Incomplete-Copy

   Description:
      Request delivery report generation
      Body parts are missing.

   Applicable protocol: Mail (http://www.rfc-editor.org/rfc/rfc2822.txt) [19]

   Status: standards-track

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

   Specification document(s):
      http://www.rfc-editor.org/rfc/rfc2156.txt
      RFC 2156 [11]

   Related information:
      Indicates whether a delivery report is wanted at successful
      delivery. Default is not to generate such a report.
      Body parts are missing. RFC 2156 (MIXER), not for general usage.


2.1.42 use.


2.1.53 Header field: Prevent-NonDelivery-Report Priority

   Description:
      Non-delivery report required?
      Message priority




Klyne & Palme           Expires August 19, October 12, 2004               [Page 26] 31]

Internet-Draft       Mail/MIME header registration         February            April 2004


   Applicable protocol: Mail (http://www.rfc-editor.org/rfc/rfc2822.txt) [19]

   Status: standards-track

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

   Specification document(s):
      http://www.rfc-editor.org/rfc/rfc2156.txt
      RFC 2156 [11]

   Related information:
      Indicates whether non-delivery report is wanted on delivery error.
      Default is to generate such a report.
      Can be 'normal', 'urgent' or 'non-urgent' and can influence
      transmission speed and delivery. RFC 2156 (MIXER), not for general usage.


2.1.43
      use.


2.1.54 Header field: Obsoletes Sensitivity

   Description:
      Reference message to be replaced
      Message content sensitivity

   Applicable protocol: Mail (http://www.rfc-editor.org/rfc/rfc2822.txt) [19]

   Status: standards-track

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

   Specification document(s):
      http://www.rfc-editor.org/rfc/rfc2156.txt
      RFC 2156 [11]

   Related information:
      Reference
      How sensitive it is to a previous disclose this message being corrected and replaced.
      Compare to 'Supersedes:' used in Usenet News. This other people than
      the specified recipients. Values: Personal, private, company
      confidential. The absence of this header field may in messages
      gatewayed from X.400 indicates that the future be replaced message is not sensitive.
      Proposed for use with a different name. RFC 2156 (MIXER),
      not for general usage.


2.1.44 (MIXER) and RFC 2421 (VPIM).


2.1.55 Header field: Content-Identifier Language

   Description:
      X.400 message content lenguage






Klyne & Palme           Expires August 19, October 12, 2004               [Page 27] 32]

Internet-Draft       Mail/MIME header registration         February            April 2004


   Description:
      Message content identifier


   Applicable protocol: Mail (http://www.rfc-editor.org/rfc/rfc2822.txt) [19]

   Status: standards-track

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

   Specification document(s):
      http://www.rfc-editor.org/rfc/rfc2156.txt
      RFC 2156 [11]

   Related information:
      A text string which identifies
      Can include a code for the content of natural language used in a message. message,
      e.g. 'en' for English. See also 'Content-Language'. RFC 2156
      (MIXER), not for general usage.


2.1.45 use.


2.1.56 Header field: Delivery-Date Conversion

   Description:
      Message delivery time
      Conversion allowed?

   Applicable protocol: Mail (http://www.rfc-editor.org/rfc/rfc2822.txt) [19]

   Status: standards-track

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

   Specification document(s):
      http://www.rfc-editor.org/rfc/rfc2156.txt
      RFC 2156 [11]

   Related information:
      The time when a body of this message was delivered may not be converted from one character
      set to its recipient. another.  Values: Prohibited and allowed. RFC 2156 (MIXER),
      not for general use.


2.1.46


2.1.57 Header field: Expiry-Date Conversion-With-Loss

   Description:
      Lossy conversion allowed?

   Applicable protocol: Mail [19]






Klyne & Palme           Expires August 19, October 12, 2004               [Page 28] 33]

Internet-Draft       Mail/MIME header registration         February            April 2004


   Description:
      Message expiry time

   Applicable protocol:
      Mail (http://www.rfc-editor.org/rfc/rfc2822.txt)


   Status: standards-track

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

   Specification document(s):
      http://www.rfc-editor.org/rfc/rfc2156.txt
      RFC 2156 [11]

   Related information:
      Time at which a
      The body of this message loses its validity. This field may in the
      future not be replaced by 'Expires:'. converted from one character
      set to another if information will be lost. Values: Prohibited and
      allowed. RFC 2156 (MIXER), not for general use.


2.1.47


2.1.58 Header field: Reply-By Message-Type

   Description:
      Time by which a reply is requested
      Message type: delivery report?

   Applicable protocol: Mail (http://www.rfc-editor.org/rfc/rfc2822.txt) [19]

   Status: standards-track

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

   Specification document(s):
      http://www.rfc-editor.org/rfc/rfc2156.txt
      RFC 2156 [11]

   Related information:
      Latest time at which a reply
      Only used with the value 'Delivery Report' to indicates that this
      is requested (not demanded). a delivery report gatewayed from X.400. RFC 2156 (MIXER), not
      for general usage.


2.1.48 use.


2.1.59 Header field: Importance Autosubmitted

   Description:
      Automatically submitted indicator

   Applicable protocol: Mail [19]

   Status: standards-track






Klyne & Palme           Expires August 19, October 12, 2004               [Page 29] 34]

Internet-Draft       Mail/MIME header registration         February            April 2004


   Description:
      Message importance

   Applicable protocol:
      Mail (http://www.rfc-editor.org/rfc/rfc2822.txt)

   Status:
      standards-track


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

   Specification document(s):
      http://www.rfc-editor.org/rfc/rfc2156.txt
      RFC 2156 [11]

   Related information:
      A hint from the originator to the recipients about how important a
      message is.  Values: High, normal or low. Not used to control
      transmission speed. Proposed for use with
      Has been automatically submitted. RFC 2156 (MIXER) and RFC
      2421 (VPIM).


2.1.49 (MIXER), not for
      general use.


2.1.60 Header field: Incomplete-Copy Autoforwarded

   Description:
      Body parts are missing.
      Automatically forwarded indicator

   Applicable protocol: Mail (http://www.rfc-editor.org/rfc/rfc2822.txt) [19]

   Status: standards-track

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

   Specification document(s):
      http://www.rfc-editor.org/rfc/rfc2156.txt
      RFC 2156 [11]

   Related information:
      Body parts are missing.
      Has been automatically forwarded. RFC 2156 (MIXER), not for
      general usage.


2.1.50 use.


2.1.61 Header field: Priority Discarded-X400-IPMS-Extensions

   Description:
      X.400 IPM extensions discarded

   Applicable protocol: Mail [19]

   Status: standards-track

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






Klyne & Palme           Expires August 19, October 12, 2004               [Page 30] 35]

Internet-Draft       Mail/MIME header registration         February            April 2004


   Specification document(s):
      RFC 2156 [11]

   Related information:
      Can be used in Internet mail to indicate X.400 IPM extensions
      which could not be mapped to Internet mail format. RFC 2156
      (MIXER), not for general use.


2.1.62 Header field: Discarded-X400-MTS-Extensions

   Description:
      Message priority
      X.400 MTS extensions discarded

   Applicable protocol: Mail (http://www.rfc-editor.org/rfc/rfc2822.txt) [19]

   Status: standards-track

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

   Specification document(s):
      http://www.rfc-editor.org/rfc/rfc2156.txt
      RFC 2156 [11]

   Related information:
      Can be 'normal', 'urgent' or 'non-urgent' and can influence
      transmission speed and delivery. used in Internet mail to indicate X.400 MTS extensions
      which could not be mapped to Internet mail format. RFC 2156
      (MIXER), not for general use.


2.1.51


2.1.63 Header field: Sensitivity Disclose-Recipients

   Description:
      Message content sensitivity
      Disclose names of other recipients?

   Applicable protocol: Mail (http://www.rfc-editor.org/rfc/rfc2822.txt) [19]

   Status: standards-track

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

   Specification document(s):
      http://www.rfc-editor.org/rfc/rfc2156.txt
      RFC 2156 [11]





Klyne & Palme           Expires October 12, 2004               [Page 36]

Internet-Draft       Mail/MIME header registration            April 2004


   Related information:
      How sensitive it is
      Tells whether recipients are to disclose be told the names of other
      recipients of the same message.  This is primarily an X.400
      facility.  In X.400, this message is an envelope attribute and refers to other people than
      disclosure of the specified recipients. Values: Personal, private, company
      confidential. The absence envelope recipient list. Disclosure of this header field other
      recipients is in messages
      gatewayed from X.400 indicates that Internet mail done via the To:, cc: and bcc:
      header fields.  Not for general use.


2.1.64 Header field: Deferred-Delivery

   Description:
      Deferred delivery information

   Applicable protocol: Mail [19]

   Status: standards-track

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

   Specification document(s):
      RFC 2156 [11]

   Related information:
      Provides information about deferred delivery service to the message is
      recipient. RFC 2156 (MIXER), not sensitive.
      Proposed for use with general use.


2.1.65 Header field: Latest-Delivery-Time

   Description:
      Latest delivery time requested

   Applicable protocol: Mail [19]

   Status: standards-track

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

   Specification document(s):
      RFC 2156 (MIXER) and RFC 2421 (VPIM). [11]






Klyne & Palme           Expires August 19, October 12, 2004               [Page 31] 37]

Internet-Draft       Mail/MIME header registration         February            April 2004


2.1.52


   Related information:
      Provides the recipient information about requested delivery, but
      will not be acted on by the SMTP infrastrucuture. RFC 2156
      (MIXER), not for general use.


2.1.66 Header field: Language Originator-Return-Address

   Description:
      X.400 message content lenguage
      Originator return address

   Applicable protocol: Mail (http://www.rfc-editor.org/rfc/rfc2822.txt) [19]

   Status: standards-track

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

   Specification document(s):
      http://www.rfc-editor.org/rfc/rfc2156.txt
      RFC 2156 [11]

   Related information:
      Can include a code for the natural language used in a message,
      e.g. 'en' for English. See also 'Content-Language'.
      Originator return address. RFC 2156 (MIXER), not for general usage.


2.1.53 use.


2.1.67 Header field: Conversion X400-Content-Identifier

   Description:
      Conversion allowed?
      Message content identifier

   Applicable protocol: Mail (http://www.rfc-editor.org/rfc/rfc2822.txt) [19]

   Status: standards-track

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

   Specification document(s):
      http://www.rfc-editor.org/rfc/rfc2156.txt
      RFC 2156 [11]

   Related information:
      The body
      A text string which identifies the content of this message may not be converted from one character
      set to another.  Values: Prohibited and allowed. a message. Renamed
      version of obsolete Content-Identifier field. RFC 2156 (MIXER),
      not for general use.





Klyne & Palme           Expires August 19, October 12, 2004               [Page 32] 38]

Internet-Draft       Mail/MIME header registration         February            April 2004


2.1.54


2.1.68 Header field: Conversion-With-Loss X400-Content-Return

   Description:
      Lossy conversion allowed?
      Return content on non-delivery?

   Applicable protocol: Mail (http://www.rfc-editor.org/rfc/rfc2822.txt) [19]

   Status: standards-track

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

   Specification document(s):
      http://www.rfc-editor.org/rfc/rfc2156.txt
      RFC 2156 [11]

   Related information:
      The body
      Indicates whether the content of this a message may not be converted from one character
      set is to another if information will be lost. Values: Prohibited and
      allowed. returned with
      non-delivery notifications. Renamed version of obsolete
      Content-Return field. RFC 2156 (MIXER), not for general use.


2.1.55


2.1.69 Header field: Message-Type X400-Content-Type

   Description:
      Message type: delivery report?
      X400 content type

   Applicable protocol: Mail (http://www.rfc-editor.org/rfc/rfc2822.txt) [19]

   Status: standards-track

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

   Specification document(s):
      http://www.rfc-editor.org/rfc/rfc2156.txt
      RFC 2156 [11]

   Related information:
      Only used with the value 'Delivery Report' to indicates that this
      is a delivery report gatewayed from X.400.
      X400 content type. RFC 2156 (MIXER), not for general use.


2.1.70 Header field: X400-MTS-Identifier

   Description:
      X400 MTS-Identifier





Klyne & Palme           Expires August 19, October 12, 2004               [Page 33] 39]

Internet-Draft       Mail/MIME header registration         February            April 2004


2.1.56 Header field: Autoforwarded

   Description:
      Automatically forwarded indicator


   Applicable protocol: Mail (http://www.rfc-editor.org/rfc/rfc2822.txt) [19]

   Status: standards-track

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

   Specification document(s):
      http://www.rfc-editor.org/rfc/rfc2156.txt
      RFC 2156 [11]

   Related information:
      Has been automatically forwarded.
      X400 MTS-Identifier. RFC 2156 (MIXER), not for general usage.


2.1.57 use.


2.1.71 Header field: Discarded-X400-IPMS-Extensions X400-Originator

   Description:
      X.400 IPM extensions discarded
      X400 Originator

   Applicable protocol: Mail (http://www.rfc-editor.org/rfc/rfc2822.txt) [19]

   Status: standards-track

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

   Specification document(s):
      http://www.rfc-editor.org/rfc/rfc2156.txt
      RFC 2156 [11]

   Related information:
      Can be used in Internet mail to indicate X.400 IPM extensions
      which could not be mapped to Internet mail format.
      X400 Originator. RFC 2156 (MIXER), not for general usage. use.


2.1.72 Header field: X400-Received

   Description:
      X400 Received

   Applicable protocol: Mail [19]

   Status: standards-track

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




Klyne & Palme           Expires August 19, October 12, 2004               [Page 34] 40]

Internet-Draft       Mail/MIME header registration         February            April 2004


2.1.58


   Specification document(s):
      RFC 2156 [11]

   Related information:
      X400 Received. RFC 2156 (MIXER), not for general use.


2.1.73 Header field: Discarded-X400-MTS-Extensions X400-Recipients

   Description:
      X.400 MTS extensions discarded
      X400 Recipients

   Applicable protocol: Mail (http://www.rfc-editor.org/rfc/rfc2822.txt) [19]

   Status: standards-track

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

   Specification document(s):
      http://www.rfc-editor.org/rfc/rfc2156.txt
      RFC 2156 [11]

   Related information:
      Can be used in Internet mail to indicate X.400 MTS extensions
      which could not be mapped to Internet mail format.
      X400 Recipients. RFC 2156 (MIXER), not for general usage.


2.1.59 use.


2.1.74 Header field: Disclose-Recipients X400-Trace

   Description:
      Disclose names of other recipients?
      X400 Trace

   Applicable protocol: Mail (http://www.rfc-editor.org/rfc/rfc2822.txt) [19]

   Status: standards-track

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

   Specification document(s):
      http://www.rfc-editor.org/rfc/rfc2156.txt
      RFC 2156 [11]

   Related information:
      Tells whether recipients are to be told the names of other
      recipients of the same message.  This is primarily an X.400
      facility.  In X.400, this is an envelope attribute and refers to
      disclosure of the envelope recipient list. Disclosure of other
      recipients is in Internet mail done via the To:, cc: and bcc:
      X400 Trace. RFC 2156 (MIXER), not for general use.






Klyne & Palme           Expires August 19, October 12, 2004               [Page 35] 41]

Internet-Draft       Mail/MIME header registration         February            April 2004


      header fields.  Not for general use.


2.2 Permanent MIME header field registrations


   Header name         Protocol
   -----------         --------
   MIME-Version        MIME      MIME version number
   Content-ID          MIME      Identify content body part
   Content-Description MIME      Description of message body part
   Content-Transfer-Encoding
                       MIME      Content transfer encoding applied
   Content-Type        MIME      MIME content type
   Content-Base        MIME      Base to be used for resolving
                                 relative URIs within this content
                                 part.
   Content-Location    MIME      URI for retrieving a body part
   Content-features    MIME      Indicates content features of a
                                 MIME body part
   Content-Disposition MIME      Intended content disposition and
                                 file name
   Content-Language    MIME      Language of message content
   Content-Alternative MIME      Alternative content available
   Content-MD5         MIME      MD5 checksum of content
   Content-Duration    MIME      Time duration of content

               Figure 2 2: MIMEHeaderPermanentRegistry.xml


2.2.1 Header field: MIME-Version

   Description:
      MIME version number

   Applicable protocol: MIME (http://www.rfc-editor.org/rfc/rfc2045.txt) [7]

   Status: standards-track

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

   Specification document(s):
      http://www.rfc-editor.org/rfc/rfc2045.txt
      RFC 2045 [7] (section 4)





Klyne & Palme           Expires August 19, 2004                [Page 36]

Internet-Draft       Mail/MIME header registration         February 2004

   Related information:
      An indicator that this message is formatted according to the MIME
      standard, and an indication of which version of MIME is utilized.





Klyne & Palme           Expires October 12, 2004               [Page 42]

Internet-Draft       Mail/MIME header registration            April 2004


2.2.2 Header field: Content-ID

   Description:
      Identify content body part

   Applicable protocol: MIME (http://www.rfc-editor.org/rfc/rfc2045.txt) [7]

   Status: standards-track

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

   Specification document(s):
      http://www.rfc-editor.org/rfc/rfc2045.txt
      RFC 2045 [7] (section 7)

   Related information:
      Specifies a Unique ID for one MIME body part of the content of a
      message.


2.2.3 Header field: Content-Description

   Description:
      Description of message body part

   Applicable protocol: MIME (http://www.rfc-editor.org/rfc/rfc2045.txt) [7]

   Status: standards-track

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

   Specification document(s):
      http://www.rfc-editor.org/rfc/rfc2045.txt (section 8)






Klyne & Palme           Expires August 19, 2004                [Page 37]

Internet-Draft       Mail/MIME header registration         February 2004
      RFC 2045 [7] (section 8)

   Related information:
      Description of a particular body part of a message, for example a
      caption for an image body part.


2.2.4 Header field: Content-Transfer-Encoding

   Description:
      Content transfer encoding applied





Klyne & Palme           Expires October 12, 2004               [Page 43]

Internet-Draft       Mail/MIME header registration            April 2004


   Applicable protocol: MIME (http://www.rfc-editor.org/rfc/rfc2045.txt) [7]

   Status: standards-track

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

   Specification document(s):
      http://www.rfc-editor.org/rfc/rfc2045.txt
      RFC 2045 [7] (section 6)

   Related information:
      Coding method used in a MIME message body part.


2.2.5 Header field: Content-Type

   Description:
      MIME content type

   Applicable protocol: MIME (http://www.rfc-editor.org/rfc/rfc2045.txt) [7]

   Status: standards-track

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

   Specification document(s):
      http://www.rfc-editor.org/rfc/rfc2045.txt
      RFC 2045 [7] (section 5)

   Related information:
      Format of content (character set etc.) Note that the values for
      this header field are defined in different ways in RFC 1049 and in



Klyne & Palme           Expires August 19, 2004                [Page 38]

Internet-Draft       Mail/MIME header registration         February 2004
      MIME (RFC 2045), look for the 'MIME-version' header field to
      understand if Content-Type is to be interpreted according to RFC
      1049 or according to MIME. The MIME definition should be used in
      generating mail. RFC 1049 has 'historic' status.  RFC 1766 defines
      a parameter 'difference' to this header field. Various other
      Content-Type define various additional parameters. For example,
      the parameter 'charset' is mandatory for all textual
      Content-Types. See also: RFC 1049,  RFC 1123: 5.2.13,  RFC 1766:
      4.1.


2.2.6 Header field: Content-Base





Klyne & Palme           Expires October 12, 2004               [Page 44]

Internet-Draft       Mail/MIME header registration            April 2004


   Description:
      Base to be used for resolving relative URIs within this content
      part.

   Applicable protocol: MIME (http://www.rfc-editor.org/rfc/rfc2045.txt) [7]

   Status: standards-track

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

   Specification document(s):
      http://www.rfc-editor.org/rfc/rfc2110.txt
      RFC 2110 [9]

   Related information:
      Base to be used for resolving relative URIs within this content
      part.  See also Content-Location. This header was included in the
      first version of MHTML and HTTP 1.1 but removed in the second
      version (RFC2557).


2.2.7 Header field: Content-Location

   Description:
      URI for retrieving a body part

   Applicable protocol: MIME (http://www.rfc-editor.org/rfc/rfc2045.txt) [7]

   Status: standards-track






Klyne & Palme           Expires August 19, 2004                [Page 39]

Internet-Draft       Mail/MIME header registration         February 2004

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

   Specification document(s):
      http://www.rfc-editor.org/rfc/rfc2110.txt
      RFC 2557 [17]

   Related information:
      URI using which the content of this body-part part was retrieved,
      might be retrievable, or which otherwise gives a globally unique
      identification of the content.


2.2.8 Header field: Content-features






Klyne & Palme           Expires October 12, 2004               [Page 45]

Internet-Draft       Mail/MIME header registration            April 2004


   Description:
      Indicates content features of a MIME body part

   Applicable protocol: MIME (http://www.rfc-editor.org/rfc/rfc2045.txt) [7]

   Status: standards-track

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

   Specification document(s):
      http://www.rfc-editor.org/rfc/rfc2912.txt
      RFC 2912 [20] (section 3)

   Related information:
      The 'Content-features:' header can be used to annotate a MIME body
      part with a media feature expression, to indicate features of the
      body part content. See also: RFC 2533, RFC 2506, RFC 2045.


2.2.9 Header field: Content-Disposition

   Description:
      Intended content disposition and file name

   Applicable protocol: MIME (http://www.rfc-editor.org/rfc/rfc2045.txt) [7]

   Status: experimental




Klyne & Palme           Expires August 19, 2004                [Page 40]

Internet-Draft       Mail/MIME header registration         February 2004

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

   Specification document(s):
      http://www.rfc-editor.org/rfc/rfc2183.txt
      RFC 2183 [12]

   Related information:
      Whether a MIME body part is to be shown inline or is an
      attachment; can also indicate a suggested filename for use when
      saving an attachment to a file.


2.2.10 Header field: Content-Language

   Description:
      Language of message content





Klyne & Palme           Expires October 12, 2004               [Page 46]

Internet-Draft       Mail/MIME header registration            April 2004


   Applicable protocol: MIME (http://www.rfc-editor.org/rfc/rfc2045.txt) [7]

   Status: standards-track

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

   Specification document(s):
      http://www.rfc-editor.org/rfc/rfc3282.txt
      RFC 3282 [22]

   Related information:
      Can include a code for the natural language used in a message,
      e.g. 'en' for English. Can also contain a list of languages for a
      message containing more than one language.


2.2.11 Header field: Content-Alternative

   Description:
      Alternative content available

   Applicable protocol: MIME (http://www.rfc-editor.org/rfc/rfc2045.txt) [7]

   Status: work-in-progress




Klyne & Palme           Expires August 19, 2004                [Page 41]

Internet-Draft       Mail/MIME header registration         February 2004

   Author/change controller:
      IETF  (mailto:iesg@ietf.org)
      Internet Engineering Task Force.
      Graham Klyne  (mailto:GK-IETF@ninebynine.org)
      Nine by Nine

   Specification document(s):
      http://www.rfc-editor.org/rfc/rfc3297.txt
      RFC 3297 [23]

   Related information:
      Information about the media features of alternative content
      formats available for the current message.


2.2.12 Header field: Content-MD5

   Description:
      MD5 checksum of content

   Applicable protocol: MIME (http://www.rfc-editor.org/rfc/rfc2045.txt) [7]

   Status: standards-track





Klyne & Palme           Expires October 12, 2004               [Page 47]

Internet-Draft       Mail/MIME header registration            April 2004


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

   Specification document(s):
      http://www.rfc-editor.org/rfc/rfc1864.txt
      RFC 1864 [6]

   Related information:
      Checksum of content to ensure that it has not been modified.


2.2.13 Header field: Content-Duration

   Description:
      Time duration of content

   Applicable protocol: MIME [7]

   Status: standards-track

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

   Specification document(s):
      RFC 2424 [16]

   Related information:
      Time duration of body part content, in seconds (e.g. for audio
      message).


3. IANA considerations

   This specification provides initial registrations of mail and MIME
   headers in the "Permanent Message Header Field Registry", defined by
   Registration procedures for message header fields [1].

4. Security considerations

   No security considerations are introduced by this specification
   beyond those already inherent in the use of message headers.

5. Acknowledgements

   Most of the information in this document has been derived from Jacob
   Palme's work in RFC 2076 [26] and subsequent updates [27].




Klyne & Palme           Expires August 19, October 12, 2004               [Page 42] 48]

Internet-Draft       Mail/MIME header registration         February            April 2004


   Palme's work in RFC 2076 [8] and subsequent updates [20].


   The authors also gratefully acknowledge the contributions of: Mark
   Nottingham, Bruce Lilly, [[[...]]]

References

Normative references

   [1]   Klyne, G., Nottingham, M. and J. Mogul, "Registration
         procedures for message headers", Oct 2003, <http://
         www.ietf.org/internet-drafts/
         draft-klyne-msghdr-registry-07.txt>.

   [2]   Hardcastle-Kille, S., "Mapping between X.400(1988) / ISO 10021
         and RFC 822", RFC 1327, May 1992.

   [3]   Alvestrand, H., Jordan, K. and J. Romaguera, "Rules for
         downgrading messages from X.400/88 to X.400/84 when MIME
         content-types are present in the messages", RFC 1496, August
         1993.

   [3]

   [4]   Costanzo, A., Robinson, D. and R. Ullmann, "Encoding Header
         Field for Internet Messages", RFC 1505, August 1993.

   [4]

   [5]   Alvestrand, H., "Tags for the Identification of Languages", RFC
         1766, March 1995.

   [5]

   [6]   Myers, J. and M. Rose, "The Content-MD5 Header Field", RFC
         1864, October 1995.

   [6]

   [7]   Freed, N. and N. Borenstein, "Multipurpose Internet Mail
         Extensions (MIME) Part One: Format of Internet Message Bodies",
         RFC 2045, November 1996.

   [7]

   [8]   Freed, N. and N. Borenstein, "Multipurpose Internet Mail
         Extensions (MIME) Part Two: Media Types", RFC 2046, November
         1996.

   [8]   Palme, J., "Common Internet Message Headers", RFC 2076,
         February 1997.

   [9]   Palme, J. and A. Hopmann, "MIME E-mail Encapsulation of
         Aggregate Documents, such as HTML (MHTML)", RFC 2110, March
         1997.

   [10]  Bradner, S., "Key words for use in RFCs to Indicate Requirement
         Levels", BCP 14, RFC 2119, March 1997.

   [11]  Kille, S., "MIXER (Mime Internet X.400 Enhanced Relay): Mapping
         between X.400 and RFC 822/MIME", RFC 2156, January 1998.

   [12]  Troost, R., Dorner, S. and K. Moore, "Communicating



Klyne & Palme           Expires August 19, 2004                [Page 43]

Internet-Draft       Mail/MIME header registration         February 2004
         Presentation Information in Internet Messages: The
         Content-Disposition Header Field", RFC 2183, August 1997.



Klyne & Palme           Expires October 12, 2004               [Page 49]

Internet-Draft       Mail/MIME header registration            April 2004


   [13]  Fajman, R., "An Extensible Message Format for Message
         Disposition Notifications", RFC 2298, March 1998.

   [14]  Neufeld, G. and J. Baer, "The Use of URLs as Meta-Syntax for
         Core Mail List Commands and their Transport through Message
         Header Fields", RFC 2369, July 1998.

   [15]  Vaudreuil, G. and G. Parsons, "Voice Profile for Internet Mail
         - version 2", RFC 2421, September 1998.

   [16]  Vaudreuil, G. and G. Parsons, "Content Duration MIME Header
         Definition", RFC 2424, September 1998.

   [17]  Palme, F., Hopmann, A., Shelness, N. and E. Stefferud, "MIME
         Encapsulation of Aggregate Documents, such as HTML (MHTML)",
         RFC 2557, March 1999.

   [18]  Klensin, J., "Simple Mail Transfer Protocol", RFC 2821, April
         2001.

   [17]

   [19]  Resnick, P., "Internet Message Format", RFC 2822, April 2001.

   [18]

   [20]  Klyne, G., "Indicating Media Features for MIME Content", RFC
         2912, September 2000.

   [19]

   [21]  Chandhok, R. and G. Wenger, "List-Id: A Structured Field and
         Namespace for the Identification of Mailing Lists", RFC 2919,
         March 2001.

   [20]

   [22]  Alvestrand, H., "Content Language Headers", RFC 3282, May 2002.

   [23]  Klyne, G., Iwazaki, R. and D. Crocker, "Content Negotiation for
         Messaging Services based on Email", RFC 3297, July 2002.

   [24]  Burger, E., Candell, E., Eliot, C. and G. Klyne, "Message
         Context for Internet Mail", RFC 3458, January 2003.

   [25]  Miller, J., Krauskopf, T., Resnick, P. and W. Treese, "PICS
         Label Distribution Label Syntax and Communication Protocols",
         W3C Recommendation REC-PICS-labels, October 1996, <http://
         www.w3.org/TR/REC-PICS-labels>.

Informative references

   [26]  Palme, J., "Common Internet Message Headers", RFC 2076,
         February 1997.

   [27]  Palme, J., "Common Internet Message Header Fields", Internet



Klyne & Palme           Expires October 12, 2004               [Page 50]

Internet-Draft       Mail/MIME header registration            April 2004


         draft draft-palme-mailext-headers-06, November 2001, <http://
         search.ietf.org/internet-drafts/
         draft-palme-mailext-headers-05.txt>.

   [21]

URIs

   [28]  <http://www.ninebynine.org/IETF/Messaging/HdrRegistry/
         Intro.html>


Authors' Addresses

   Graham Klyne
   Nine by Nine
   UK

   EMail: GK-IETF@ninebynine.org
   URI:   http://www.ninebynine.net/









Klyne & Palme           Expires August 19, 2004                [Page 44]

Internet-Draft       Mail/MIME header registration         February 2004


   Jacob Palme
   Stockholm University/KTH
   Forum 100
   Kista  S-164 40
   Sweden

   Phone: +46-8-16 16 67
   EMail: jpalme@dsv.su.se

Appendix A. Revision history

   [[[Please remove this section on final publication]]]

A.1 draft-klyne-hdrreg-mail-03

   03c 13-Apr-2004:

      *  Added Accept-Language header, with some warning text concerning
         its use with email.

      *  Removed Originator headere, since it is not used as a mail
         message header.

      *  Fix up report generator error in author/change controller
         handling.






Klyne & Palme           Expires October 12, 2004               [Page 51]

Internet-Draft       Mail/MIME header registration            April 2004


   03b 06-Apr-2004:

      *  Using a new version of the RDF-to-documentation generator for
         registry entry data.

      *  Revised format of registry entries to avoid some duplication of
         document and author details.

      *  Added documents referenced by the regsitration entries to the
         references section, and added citations to the entries
         themselves.

   03a 15-Mar-2004:

      *  Added and revised header details, per comments from Bruce
         Lilly.


A.2 draft-klyne-hdrreg-mail-02

   02d 19-Feb-2004:

      *  Incorporated small changes to specific header field
         descriptions, suggested by Jacob.

   02c 18-Feb-2004:

      *  Separated Mail and MIME header fields.

      *  Corrected specification reference for MIXER headers (RFC 2156).

      *  Changed applicable protocol for MIME header fields.

      *  Other smaller corrections.

   02b 17-Feb-2004:

      *  Removed provisional mail header registrations from this
         document.

   02a 05-Aug-2002:

      *  Added Jacob Palme as co-editor.


A.2


A.3 draft-klyne-hdrreg-mail-01

   01c 05-Jun-2002:

      *  Minor editorial.





Klyne & Palme           Expires August 19, October 12, 2004               [Page 45] 52]

Internet-Draft       Mail/MIME header registration         February            April 2004


   01c 05-Jun-2002:

      *  Minor editorial.

   01b 10-May-2002:

      *  Updated some contact information.

      *  Regenerated registry tables with revised software.

   01a 08-May-2002:

      *  Revised change controller information in line with registry
         specification.

      *  Cleaned up some table layout.


A.3


A.4 draft-klyne-hdrreg-mail-00

   00c 05-May-2002:

      *  Added data for permanent and provisional registries.

   00b 01-May-2002:

      *  Revised form of registry entry content. (Auto-generated from
         RDF data.)

   00a 22-Jan-2002:

      *  Document initially created.


Appendix B. TODO:

   [[[Please remove this section on final publication]]]

   o  Review format of header descriptions: may want to make this more
      compact.











Klyne & Palme           Expires August 19, October 12, 2004               [Page 46] 53]

Internet-Draft       Mail/MIME header registration         February            April 2004


Intellectual Property Statement

   The IETF takes no position regarding the validity or scope of any
   intellectual property 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; neither does it represent that it
   has made any effort to identify any such rights. Information on the
   IETF's procedures with respect to rights in standards-track and
   standards-related documentation can be found in BCP-11. Copies of
   claims of rights made available for publication 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 implementors or users of this specification can
   be obtained from the IETF Secretariat.

   The IETF invites any interested party to bring to its attention any
   copyrights, patents or patent applications, or other proprietary
   rights which may cover technology that may be required to practice
   this standard. Please address the information to the IETF Executive
   Director.


Full Copyright Statement

   Copyright (C) The Internet Society (2004). All Rights Reserved.

   This document and translations of it may be copied and furnished to
   others, and derivative works that comment on or otherwise explain it
   or assist in its implementation may be prepared, copied, published
   and distributed, in whole or in part, without restriction of any
   kind, provided that the above copyright notice and this paragraph are
   included on all such copies and derivative works. However, this
   document itself may not be modified in any way, such as by removing
   the copyright notice or references to the Internet Society or other
   Internet organizations, except as needed for the purpose of
   developing Internet standards in which case the procedures for
   copyrights defined in the Internet Standards process must be
   followed, or as required to translate it into languages other than
   English.

   The limited permissions granted above are perpetual and will not be
   revoked by the Internet Society or its successors or assignees.

   This document and the information contained herein is provided on an
   "AS IS" basis and THE INTERNET SOCIETY AND THE INTERNET ENGINEERING
   TASK FORCE DISCLAIMS ALL WARRANTIES, EXPRESS OR IMPLIED, INCLUDING
   BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE INFORMATION



Klyne & Palme           Expires August 19, October 12, 2004               [Page 47] 54]

Internet-Draft       Mail/MIME header registration         February            April 2004


   HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED WARRANTIES OF
   MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.


Acknowledgement

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











































Klyne & Palme           Expires August 19, October 12, 2004               [Page 48] 55]

----