4021
PROPOSED STANDARD
Registration of Mail and MIME Header Fields
Authors: G. Klyne, J. Palme
Date: March 2005
Working Group: NON WORKING GROUP
Stream: IETF
Updated by:
RFC 5322
Abstract
This document defines the initial IANA registration for permanent mail and MIME message header fields, per RFC 3864. [STANDARDS-TRACK]
RFC 4021
PROPOSED STANDARD
Updated by: 5322
Network Working Group G. Klyne
Request for Comments: 4021 University of Oxford
Category: Standards Track J. Palme
Stockholm University/KT
March 2005
<span class="h1">Registration of Mail and MIME Header Fields</span>
Status of This Memo
This document specifies an Internet standards track protocol for the
Internet community, and requests discussion and suggestions for
improvements. Please refer to the current edition of the "Internet
Official Protocol Standards" (STD 1) for the standardization state
and status of this protocol. Distribution of this memo is unlimited.
Copyright Notice
Copyright (C) The Internet Society (2005).
Abstract
This document defines the initial IANA registration for permanent
mail and MIME message header fields, per <a href="./rfc3864">RFC 3864</a>.
Table of Contents
<a href="#section-1">1</a>. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . <a href="#page-3">3</a>
<a href="#section-1.1">1.1</a>. Structure of This Document . . . . . . . . . . . . . . . <a href="#page-3">3</a>
<a href="#section-1.2">1.2</a>. Document Terminology and Conventions . . . . . . . . . . <a href="#page-4">4</a>
<a href="#section-2">2</a>. Registration Templates . . . . . . . . . . . . . . . . . . . . <a href="#page-4">4</a>
<a href="#section-2.1">2.1</a>. Permanent Mail Header Field Registrations . . . . . . . <a href="#page-4">4</a>
<a href="#section-2.1.1">2.1.1</a>. Header Field: Date . . . . . . . . . . . . . . . <a href="#page-6">6</a>
<a href="#section-2.1.2">2.1.2</a>. Header Field: From . . . . . . . . . . . . . . . <a href="#page-7">7</a>
<a href="#section-2.1.3">2.1.3</a>. Header Field: Sender . . . . . . . . . . . . . . <a href="#page-7">7</a>
<a href="#section-2.1.4">2.1.4</a>. Header Field: Reply-To . . . . . . . . . . . . . <a href="#page-8">8</a>
<a href="#section-2.1.5">2.1.5</a>. Header Field: To . . . . . . . . . . . . . . . . <a href="#page-8">8</a>
<a href="#section-2.1.6">2.1.6</a>. Header Field: Cc . . . . . . . . . . . . . . . . <a href="#page-9">9</a>
<a href="#section-2.1.7">2.1.7</a>. Header Field: Bcc . . . . . . . . . . . . . . . <a href="#page-9">9</a>
<a href="#section-2.1.8">2.1.8</a>. Header Field: Message-ID . . . . . . . . . . . . <a href="#page-10">10</a>
<a href="#section-2.1.9">2.1.9</a>. Header Field: In-Reply-To . . . . . . . . . . . <a href="#page-10">10</a>
<a href="#section-2.1.10">2.1.10</a>. Header Field: References . . . . . . . . . . . . <a href="#page-11">11</a>
<a href="#section-2.1.11">2.1.11</a>. Header Field: Subject . . . . . . . . . . . . . <a href="#page-11">11</a>
<a href="#section-2.1.12">2.1.12</a>. Header Field: Comments . . . . . . . . . . . . . <a href="#page-12">12</a>
<a href="#section-2.1.13">2.1.13</a>. Header Field: Keywords . . . . . . . . . . . . . <a href="#page-12">12</a>
<a href="#section-2.1.14">2.1.14</a>. Header Field: Resent-Date . . . . . . . . . . . <a href="#page-13">13</a>
<a href="#section-2.1.15">2.1.15</a>. Header Field: Resent-From . . . . . . . . . . . <a href="#page-13">13</a>
<a href="#section-2.1.16">2.1.16</a>. Header Field: Resent-Sender . . . . . . . . . . <a href="#page-14">14</a>
<span class="grey">G. Klyne, et al. Standards Track [Page 1]</span><span id="page-2" ></span>
<span class="grey"><a href="./rfc4021">RFC 4021</a> Mail and MIME Header Fields March 2005</span>
<a href="#section-2.1.17">2.1.17</a>. Header Field: Resent-To . . . . . . . . . . . . <a href="#page-14">14</a>
<a href="#section-2.1.18">2.1.18</a>. Header Field: Resent-Cc . . . . . . . . . . . . <a href="#page-15">15</a>
<a href="#section-2.1.19">2.1.19</a>. Header Field: Resent-Bcc . . . . . . . . . . . . <a href="#page-15">15</a>
<a href="#section-2.1.20">2.1.20</a>. Header Field: Resent-Reply-To . . . . . . . . . <a href="#page-16">16</a>
<a href="#section-2.1.21">2.1.21</a>. Header Field: Resent-Message-ID . . . . . . . . <a href="#page-16">16</a>
<a href="#section-2.1.22">2.1.22</a>. Header Field: Return-Path . . . . . . . . . . . <a href="#page-17">17</a>
<a href="#section-2.1.23">2.1.23</a>. Header Field: Received . . . . . . . . . . . . . <a href="#page-17">17</a>
<a href="#section-2.1.24">2.1.24</a>. Header Field: Encrypted . . . . . . . . . . . . <a href="#page-18">18</a>
<a href="#section-2.1.25">2.1.25</a>. Header Field: Disposition-Notification-To . . . <a href="#page-18">18</a>
2.1.26. Header Field: Disposition-Notification-Options . 19
<a href="#section-2.1.27">2.1.27</a>. Header Field: Accept-Language . . . . . . . . . <a href="#page-19">19</a>
<a href="#section-2.1.28">2.1.28</a>. Header Field: Original-Message-ID . . . . . . . <a href="#page-20">20</a>
<a href="#section-2.1.29">2.1.29</a>. Header Field: PICS-Label . . . . . . . . . . . . <a href="#page-20">20</a>
<a href="#section-2.1.30">2.1.30</a>. Header Field: Encoding . . . . . . . . . . . . . <a href="#page-21">21</a>
<a href="#section-2.1.31">2.1.31</a>. Header Field: List-Archive . . . . . . . . . . . <a href="#page-21">21</a>
<a href="#section-2.1.32">2.1.32</a>. Header Field: List-Help . . . . . . . . . . . . <a href="#page-22">22</a>
<a href="#section-2.1.33">2.1.33</a>. Header Field: List-ID . . . . . . . . . . . . . <a href="#page-22">22</a>
<a href="#section-2.1.34">2.1.34</a>. Header Field: List-Owner . . . . . . . . . . . . <a href="#page-23">23</a>
<a href="#section-2.1.35">2.1.35</a>. Header Field: List-Post . . . . . . . . . . . . <a href="#page-23">23</a>
<a href="#section-2.1.36">2.1.36</a>. Header Field: List-Subscribe . . . . . . . . . . <a href="#page-24">24</a>
<a href="#section-2.1.37">2.1.37</a>. Header Field: List-Unsubscribe . . . . . . . . . <a href="#page-24">24</a>
<a href="#section-2.1.38">2.1.38</a>. Header Field: Message-Context . . . . . . . . . <a href="#page-25">25</a>
<a href="#section-2.1.39">2.1.39</a>. Header Field: DL-Expansion-History . . . . . . . <a href="#page-25">25</a>
<a href="#section-2.1.40">2.1.40</a>. Header Field: Alternate-Recipient . . . . . . . <a href="#page-26">26</a>
2.1.41. Header Field: Original-Encoded-Information-Types 26
<a href="#section-2.1.42">2.1.42</a>. Header Field: Content-Return . . . . . . . . . . <a href="#page-27">27</a>
<a href="#section-2.1.43">2.1.43</a>. Header Field: Generate-Delivery-Report . . . . . <a href="#page-27">27</a>
<a href="#section-2.1.44">2.1.44</a>. Header Field: Prevent-NonDelivery-Report . . . . <a href="#page-28">28</a>
<a href="#section-2.1.45">2.1.45</a>. Header Field: Obsoletes . . . . . . . . . . . . <a href="#page-28">28</a>
<a href="#section-2.1.46">2.1.46</a>. Header Field: Supersedes . . . . . . . . . . . . <a href="#page-29">29</a>
<a href="#section-2.1.47">2.1.47</a>. Header Field: Content-Identifier . . . . . . . . <a href="#page-29">29</a>
<a href="#section-2.1.48">2.1.48</a>. Header Field: Delivery-Date . . . . . . . . . . <a href="#page-30">30</a>
<a href="#section-2.1.49">2.1.49</a>. Header Field: Expiry-Date . . . . . . . . . . . <a href="#page-30">30</a>
<a href="#section-2.1.50">2.1.50</a>. Header Field: Expires . . . . . . . . . . . . . <a href="#page-31">31</a>
<a href="#section-2.1.51">2.1.51</a>. Header Field: Reply-By . . . . . . . . . . . . . <a href="#page-31">31</a>
<a href="#section-2.1.52">2.1.52</a>. Header Field: Importance . . . . . . . . . . . . <a href="#page-32">32</a>
<a href="#section-2.1.53">2.1.53</a>. Header Field: Incomplete-Copy . . . . . . . . . <a href="#page-32">32</a>
<a href="#section-2.1.54">2.1.54</a>. Header Field: Priority . . . . . . . . . . . . . <a href="#page-33">33</a>
<a href="#section-2.1.55">2.1.55</a>. Header Field: Sensitivity . . . . . . . . . . . <a href="#page-33">33</a>
<a href="#section-2.1.56">2.1.56</a>. Header Field: Language . . . . . . . . . . . . . <a href="#page-34">34</a>
<a href="#section-2.1.57">2.1.57</a>. Header Field: Conversion . . . . . . . . . . . . <a href="#page-34">34</a>
<a href="#section-2.1.58">2.1.58</a>. Header Field: Conversion-With-Loss . . . . . . . <a href="#page-35">35</a>
<a href="#section-2.1.59">2.1.59</a>. Header Field: Message-Type . . . . . . . . . . . <a href="#page-35">35</a>
<a href="#section-2.1.60">2.1.60</a>. Header Field: Autosubmitted . . . . . . . . . . <a href="#page-36">36</a>
<a href="#section-2.1.61">2.1.61</a>. Header Field: Autoforwarded . . . . . . . . . . <a href="#page-36">36</a>
<a href="#section-2.1.62">2.1.62</a>. Header Field: Discarded-X400-IPMS-Extensions . . <a href="#page-37">37</a>
<a href="#section-2.1.63">2.1.63</a>. Header Field: Discarded-X400-MTS-Extensions . . <a href="#page-37">37</a>
<a href="#section-2.1.64">2.1.64</a>. Header Field: Disclose-Recipients . . . . . . . <a href="#page-38">38</a>
<span class="grey">G. Klyne, et al. Standards Track [Page 2]</span><span id="page-3" ></span>
<span class="grey"><a href="./rfc4021">RFC 4021</a> Mail and MIME Header Fields March 2005</span>
<a href="#section-2.1.65">2.1.65</a>. Header Field: Deferred-Delivery . . . . . . . . <a href="#page-38">38</a>
<a href="#section-2.1.66">2.1.66</a>. Header Field: Latest-Delivery-Time . . . . . . . <a href="#page-39">39</a>
<a href="#section-2.1.67">2.1.67</a>. Header Field: Originator-Return-Address . . . . <a href="#page-39">39</a>
<a href="#section-2.1.68">2.1.68</a>. Header Field: X400-Content-Identifier . . . . . <a href="#page-40">40</a>
<a href="#section-2.1.69">2.1.69</a>. Header Field: X400-Content-Return . . . . . . . <a href="#page-40">40</a>
<a href="#section-2.1.70">2.1.70</a>. Header Field: X400-Content-Type . . . . . . . . <a href="#page-41">41</a>
<a href="#section-2.1.71">2.1.71</a>. Header Field: X400-MTS-Identifier . . . . . . . <a href="#page-41">41</a>
<a href="#section-2.1.72">2.1.72</a>. Header Field: X400-Originator . . . . . . . . . <a href="#page-42">42</a>
<a href="#section-2.1.73">2.1.73</a>. Header Field: X400-Received . . . . . . . . . . <a href="#page-42">42</a>
<a href="#section-2.1.74">2.1.74</a>. Header Field: X400-Recipients . . . . . . . . . <a href="#page-43">43</a>
<a href="#section-2.1.75">2.1.75</a>. Header Field: X400-Trace . . . . . . . . . . . . <a href="#page-43">43</a>
<a href="#section-2.2">2.2</a>. Permanent MIME Header Field Registrations . . . . . . . <a href="#page-44">44</a>
<a href="#section-2.2.1">2.2.1</a>. Header Field: MIME-Version . . . . . . . . . . . <a href="#page-44">44</a>
<a href="#section-2.2.2">2.2.2</a>. Header Field: Content-ID . . . . . . . . . . . . <a href="#page-45">45</a>
<a href="#section-2.2.3">2.2.3</a>. Header Field: Content-Description . . . . . . . <a href="#page-45">45</a>
<a href="#section-2.2.4">2.2.4</a>. Header Field: Content-Transfer-Encoding . . . . <a href="#page-46">46</a>
<a href="#section-2.2.5">2.2.5</a>. Header Field: Content-Type . . . . . . . . . . . <a href="#page-46">46</a>
<a href="#section-2.2.6">2.2.6</a>. Header Field: Content-Base . . . . . . . . . . . <a href="#page-47">47</a>
<a href="#section-2.2.7">2.2.7</a>. Header Field: Content-Location . . . . . . . . . <a href="#page-47">47</a>
<a href="#section-2.2.8">2.2.8</a>. Header Field: Content-features . . . . . . . . . <a href="#page-48">48</a>
<a href="#section-2.2.9">2.2.9</a>. Header Field: Content-Disposition . . . . . . . <a href="#page-48">48</a>
<a href="#section-2.2.10">2.2.10</a>. Header Field: Content-Language . . . . . . . . . <a href="#page-49">49</a>
<a href="#section-2.2.11">2.2.11</a>. Header Field: Content-Alternative . . . . . . . <a href="#page-49">49</a>
<a href="#section-2.2.12">2.2.12</a>. Header Field: Content-MD5 . . . . . . . . . . . <a href="#page-50">50</a>
<a href="#section-2.2.13">2.2.13</a>. Header Field: Content-Duration . . . . . . . . . <a href="#page-50">50</a>
<a href="#section-3">3</a>. IANA Considerations . . . . . . . . . . . . . . . . . . . . . <a href="#page-50">50</a>
<a href="#section-4">4</a>. Security Considerations . . . . . . . . . . . . . . . . . . . <a href="#page-51">51</a>
<a href="#section-5">5</a>. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . <a href="#page-51">51</a>
<a href="#section-6">6</a>. References . . . . . . . . . . . . . . . . . . . . . . . . . . <a href="#page-51">51</a>
<a href="#section-6.1">6.1</a>. Normative References . . . . . . . . . . . . . . . . . . <a href="#page-51">51</a>
<a href="#section-6.2">6.2</a>. Informative References . . . . . . . . . . . . . . . . . <a href="#page-53">53</a>
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . <a href="#page-53">53</a>
Full Copyright Statement . . . . . . . . . . . . . . . . . . . . . <a href="#page-54">54</a>
<span class="h2"><a class="selflink" id="section-1" href="#section-1">1</a>. Introduction</span>
This document defines IANA registration for a number of mail message
and MIME header fields, per registration procedures for message
header fields [<a href="#ref-1" title=""Registration Procedures for Message Header Fields"">1</a>].
The main body of this document is automatically generated from RDF/N3
data. Some experimental HTML registry pages have been prepared from
the same data and can be found at [<a href="#ref-27">27</a>].
<span class="h3"><a class="selflink" id="section-1.1" href="#section-1.1">1.1</a>. Structure of This Document</span>
<a href="#section-2.1">Section 2.1</a> contains the templates for initial registration of mail
message header fields.
<span class="grey">G. Klyne, et al. Standards Track [Page 3]</span><span id="page-4" ></span>
<span class="grey"><a href="./rfc4021">RFC 4021</a> Mail and MIME Header Fields March 2005</span>
<a href="#section-2.2">Section 2.2</a> contains templates for initial registration of MIME
header fields.
<span class="h3"><a class="selflink" id="section-1.2" href="#section-1.2">1.2</a>. Document Terminology and Conventions</span>
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 <a href="https://www.rfc-editor.org/bcp/bcp14">BCP 14</a>, <a href="./rfc2119">RFC 2119</a> [<a href="#ref-9" title=""Key words for use in RFCs to Indicate Requirement Levels"">9</a>].
<span class="h2"><a class="selflink" id="section-2" href="#section-2">2</a>. Registration Templates</span>
Header field registry entries are summarized in tabular form for
convenience of reference and presented in full in the following
sections.
<span class="h3"><a class="selflink" id="section-2.1" href="#section-2.1">2.1</a>. Permanent Mail Header Field Registrations</span>
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
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
<span class="grey">G. Klyne, et al. Standards Track [Page 4]</span><span id="page-5" ></span>
<span class="grey"><a href="./rfc4021">RFC 4021</a> Mail and MIME Header Fields March 2005</span>
Return-Path Mail Message return path
Received Mail Mail transfer trace information
Encrypted Mail Message encryption 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?
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 language
Conversion Mail Conversion allowed?
<span class="grey">G. Klyne, et al. Standards Track [Page 5]</span><span id="page-6" ></span>
<span class="grey"><a href="./rfc4021">RFC 4021</a> Mail and MIME Header Fields March 2005</span>
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
<span class="h4"><a class="selflink" id="section-2.1.1" href="#section-2.1.1">2.1.1</a>. Header Field: Date</span>
Description:
Message date and time
Applicable protocol: Mail [<a href="#ref-18" title=""Internet Message Format"">18</a>]
Status: standard
Author/change controller:
IETF (mailto:[email protected])
Internet Engineering Task Force
Specification document(s):
<a href="./rfc2822">RFC 2822</a> [<a href="#ref-18" title=""Internet Message Format"">18</a>] (<a href="#section-3.6.1">section 3.6.1</a>)
Related information:
Specifies the date and time at which the creator of the message
indicated that the message was complete and ready to enter the
mail delivery system. Defined as standard by <a href="./rfc822">RFC 822</a>.
<span class="grey">G. Klyne, et al. Standards Track [Page 6]</span><span id="page-7" ></span>
<span class="grey"><a href="./rfc4021">RFC 4021</a> Mail and MIME Header Fields March 2005</span>
<span class="h4"><a class="selflink" id="section-2.1.2" href="#section-2.1.2">2.1.2</a>. Header Field: From</span>
Description:
Mailbox of message author
Applicable protocol: Mail [<a href="#ref-18" title=""Internet Message Format"">18</a>]
Status: standard
Author/change controller:
IETF (mailto:[email protected])
Internet Engineering Task Force
Specification document(s):
<a href="./rfc2822">RFC 2822</a> [<a href="#ref-18" title=""Internet Message Format"">18</a>] (<a href="#section-3.6.2">section 3.6.2</a>)
Related information:
Specifies the author(s) of the message; that is, the mailbox(es)
of the person(s) or system(s) responsible for the writing of the
message. Defined as standard by <a href="./rfc822">RFC 822</a>.
<span class="h4"><a class="selflink" id="section-2.1.3" href="#section-2.1.3">2.1.3</a>. Header Field: Sender</span>
Description:
Mailbox of message sender
Applicable protocol: Mail [<a href="#ref-18" title=""Internet Message Format"">18</a>]
Status: standard
Author/change controller:
IETF (mailto:[email protected])
Internet Engineering Task Force
Specification document(s):
<a href="./rfc2822">RFC 2822</a> [<a href="#ref-18" title=""Internet Message Format"">18</a>] (<a href="#section-3.6.2">section 3.6.2</a>)
Related information:
Specifies the mailbox of the agent responsible for the actual
transmission of the message. Defined as standard by <a href="./rfc822">RFC 822</a>.
<span class="grey">G. Klyne, et al. Standards Track [Page 7]</span><span id="page-8" ></span>
<span class="grey"><a href="./rfc4021">RFC 4021</a> Mail and MIME Header Fields March 2005</span>
<span class="h4"><a class="selflink" id="section-2.1.4" href="#section-2.1.4">2.1.4</a>. Header Field: Reply-To</span>
Description:
Mailbox for replies to message
Applicable protocol: Mail [<a href="#ref-18" title=""Internet Message Format"">18</a>]
Status: standard
Author/change controller:
IETF (mailto:[email protected]) Internet Engineering Task Force
Specification document(s):
<a href="./rfc2822">RFC 2822</a> [<a href="#ref-18" title=""Internet Message Format"">18</a>] (<a href="#section-3.6.2">section 3.6.2</a>)
Related information:
When the "Reply-To:" field is present, it indicates the
mailbox(es) to which the author of the message suggests that
replies be sent. Defined as standard by <a href="./rfc822">RFC 822</a>.
<span class="h4"><a class="selflink" id="section-2.1.5" href="#section-2.1.5">2.1.5</a>. Header Field: To</span>
Description:
Primary recipient mailbox
Applicable protocol: Mail [<a href="#ref-18" title=""Internet Message Format"">18</a>]
Status: standard
Author/change controller:
IETF (mailto:[email protected])
Internet Engineering Task Force
Specification document(s):
<a href="./rfc2822">RFC 2822</a> [<a href="#ref-18" title=""Internet Message Format"">18</a>] (<a href="#section-3.6.3">section 3.6.3</a>)
Related information:
Contains the address(es) of the primary recipient(s) of the
message. Defined as standard by <a href="./rfc822">RFC 822</a>.
<span class="grey">G. Klyne, et al. Standards Track [Page 8]</span><span id="page-9" ></span>
<span class="grey"><a href="./rfc4021">RFC 4021</a> Mail and MIME Header Fields March 2005</span>
<span class="h4"><a class="selflink" id="section-2.1.6" href="#section-2.1.6">2.1.6</a>. Header Field: Cc</span>
Description:
Carbon-copy recipient mailbox
Applicable protocol: Mail [<a href="#ref-18" title=""Internet Message Format"">18</a>]
Status: standard
Author/change controller:
IETF (mailto:[email protected])
Internet Engineering Task Force
Specification document(s):
<a href="./rfc2822">RFC 2822</a> [<a href="#ref-18" title=""Internet Message Format"">18</a>] (<a href="#section-3.6.3">section 3.6.3</a>)
Related information:
Contains the addresses of others who are to receive the message,
though the content of the message may not be directed at them.
Defined as standard by <a href="./rfc822">RFC 822</a>.
<span class="h4"><a class="selflink" id="section-2.1.7" href="#section-2.1.7">2.1.7</a>. Header Field: Bcc</span>
Description:
Blind-carbon-copy recipient mailbox
Applicable protocol: Mail [<a href="#ref-18" title=""Internet Message Format"">18</a>]
Status: standard
Author/change controller:
IETF (mailto:[email protected])
Internet Engineering Task Force
Specification document(s):
<a href="./rfc2822">RFC 2822</a> [<a href="#ref-18" title=""Internet Message Format"">18</a>] (<a href="#section-3.6.3">section 3.6.3</a>)
Related information:
Contains addresses of recipients of the message whose addresses
are not to be revealed to other recipients of the message.
Defined as standard by <a href="./rfc822">RFC 822</a>.
<span class="grey">G. Klyne, et al. Standards Track [Page 9]</span><span id="page-10" ></span>
<span class="grey"><a href="./rfc4021">RFC 4021</a> Mail and MIME Header Fields March 2005</span>
<span class="h4"><a class="selflink" id="section-2.1.8" href="#section-2.1.8">2.1.8</a>. Header Field: Message-ID</span>
Description:
Message identifier
Applicable protocol: Mail [<a href="#ref-18" title=""Internet Message Format"">18</a>]
Status: standard
Author/change controller:
IETF (mailto:[email protected])
Internet Engineering Task Force
Specification document(s):
<a href="./rfc2822">RFC 2822</a> [<a href="#ref-18" title=""Internet Message Format"">18</a>] (<a href="#section-3.6.4">section 3.6.4</a>)
Related information:
Contains a single unique message identifier that refers to a
particular version of a particular message. If the message is
resent without changes, the original Message-ID is retained.
Defined as standard by <a href="./rfc822">RFC 822</a>.
<span class="h4"><a class="selflink" id="section-2.1.9" href="#section-2.1.9">2.1.9</a>. Header Field: In-Reply-To</span>
Description:
Identify replied-to message(s)
Applicable protocol: Mail [<a href="#ref-18" title=""Internet Message Format"">18</a>]
Status: standard
Author/change controller:
IETF (mailto:[email protected])
Internet Engineering Task Force
Specification document(s):
<a href="./rfc2822">RFC 2822</a> [<a href="#ref-18" title=""Internet Message Format"">18</a>] (<a href="#section-3.6.4">section 3.6.4</a>)
Related information:
The message identifier(s) of the original message(s) to which the
current message is a reply. Defined as standard by <a href="./rfc822">RFC 822</a>.
<span class="grey">G. Klyne, et al. Standards Track [Page 10]</span><span id="page-11" ></span>
<span class="grey"><a href="./rfc4021">RFC 4021</a> Mail and MIME Header Fields March 2005</span>
<span class="h4"><a class="selflink" id="section-2.1.10" href="#section-2.1.10">2.1.10</a>. Header Field: References</span>
Description:
Related message identifier(s)
Applicable protocol: Mail [<a href="#ref-18" title=""Internet Message Format"">18</a>]
Status: standard
Author/change controller:
IETF (mailto:[email protected])
Internet Engineering Task Force
Specification document(s):
<a href="./rfc2822">RFC 2822</a> [<a href="#ref-18" title=""Internet Message Format"">18</a>] (<a href="#section-3.6.4">section 3.6.4</a>)
Related information:
The message identifier(s) of other message(s) to which the current
message may be related. In <a href="./rfc2822">RFC 2822</a>, the definition was changed
to say that this header field contains a list of all Message-IDs
of messages in the preceding reply chain. Defined as standard by
<a href="./rfc822">RFC 822</a>.
<span class="h4"><a class="selflink" id="section-2.1.11" href="#section-2.1.11">2.1.11</a>. Header Field: Subject</span>
Description:
Topic of message
Applicable protocol: Mail [<a href="#ref-18" title=""Internet Message Format"">18</a>]
Status: standard
Author/change controller:
IETF (mailto:[email protected])
Internet Engineering Task Force
Specification document(s):
<a href="./rfc2822">RFC 2822</a> [<a href="#ref-18" title=""Internet Message Format"">18</a>] (<a href="#section-3.6.5">section 3.6.5</a>)
Related information:
Contains a short string identifying the topic of the message.
Defined as standard by <a href="./rfc822">RFC 822</a>.
<span class="grey">G. Klyne, et al. Standards Track [Page 11]</span><span id="page-12" ></span>
<span class="grey"><a href="./rfc4021">RFC 4021</a> Mail and MIME Header Fields March 2005</span>
<span class="h4"><a class="selflink" id="section-2.1.12" href="#section-2.1.12">2.1.12</a>. Header Field: Comments</span>
Description:
Additional comments about the message
Applicable protocol: Mail [<a href="#ref-18" title=""Internet Message Format"">18</a>]
Status: standard
Author/change controller:
IETF (mailto:[email protected])
Internet Engineering Task Force
Specification document(s):
<a href="./rfc2822">RFC 2822</a> [<a href="#ref-18" title=""Internet Message Format"">18</a>] (<a href="#section-3.6.5">section 3.6.5</a>)
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. Defined as standard by <a href="./rfc822">RFC 822</a>.
<span class="h4"><a class="selflink" id="section-2.1.13" href="#section-2.1.13">2.1.13</a>. Header Field: Keywords</span>
Description:
Message key words and/or phrases
Applicable protocol: Mail [<a href="#ref-18" title=""Internet Message Format"">18</a>]
Status: standard
Author/change controller:
IETF (mailto:[email protected])
Internet Engineering Task Force
Specification document(s):
<a href="./rfc2822">RFC 2822</a> [<a href="#ref-18" title=""Internet Message Format"">18</a>] (<a href="#section-3.6.5">section 3.6.5</a>)
Related information:
Contains a comma-separated list of important words and phrases
that might be useful for the recipient. Defined as standard by
<a href="./rfc822">RFC 822</a>.
<span class="grey">G. Klyne, et al. Standards Track [Page 12]</span><span id="page-13" ></span>
<span class="grey"><a href="./rfc4021">RFC 4021</a> Mail and MIME Header Fields March 2005</span>
<span class="h4"><a class="selflink" id="section-2.1.14" href="#section-2.1.14">2.1.14</a>. Header Field: Resent-Date</span>
Description:
Date and time message is resent
Applicable protocol: Mail [<a href="#ref-18" title=""Internet Message Format"">18</a>]
Status: standard
Author/change controller:
IETF (mailto:[email protected])
Internet Engineering Task Force
Specification document(s):
<a href="./rfc2822">RFC 2822</a> [<a href="#ref-18" title=""Internet Message Format"">18</a>] (<a href="#section-3.6.6">section 3.6.6</a>)
Related information:
Contains the date and time that a message is reintroduced into the
message transfer system. Defined as standard by <a href="./rfc822">RFC 822</a>.
<span class="h4"><a class="selflink" id="section-2.1.15" href="#section-2.1.15">2.1.15</a>. Header Field: Resent-From</span>
Description:
Mailbox of person for whom message is resent
Applicable protocol: Mail [<a href="#ref-18" title=""Internet Message Format"">18</a>]
Status: standard
Author/change controller:
IETF (mailto:[email protected])
Internet Engineering Task Force
Specification document(s):
<a href="./rfc2822">RFC 2822</a> [<a href="#ref-18" title=""Internet Message Format"">18</a>] (<a href="#section-3.6.6">section 3.6.6</a>)
Related information:
Contains the mailbox of the agent who has reintroduced the message
into the message transfer system, or on whose behalf the message
has been resent. Defined as standard by <a href="./rfc822">RFC 822</a>.
<span class="grey">G. Klyne, et al. Standards Track [Page 13]</span><span id="page-14" ></span>
<span class="grey"><a href="./rfc4021">RFC 4021</a> Mail and MIME Header Fields March 2005</span>
<span class="h4"><a class="selflink" id="section-2.1.16" href="#section-2.1.16">2.1.16</a>. Header Field: Resent-Sender</span>
Description:
Mailbox of person who actually resends the message
Applicable protocol: Mail [<a href="#ref-18" title=""Internet Message Format"">18</a>]
Status: standard
Author/change controller:
IETF (mailto:[email protected])
Internet Engineering Task Force
Specification document(s):
<a href="./rfc2822">RFC 2822</a> [<a href="#ref-18" title=""Internet Message Format"">18</a>] (<a href="#section-3.6.6">section 3.6.6</a>)
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. Defined as standard by <a href="./rfc822">RFC 822</a>.
<span class="h4"><a class="selflink" id="section-2.1.17" href="#section-2.1.17">2.1.17</a>. Header Field: Resent-To</span>
Description:
Mailbox to which message is resent
Applicable protocol: Mail [<a href="#ref-18" title=""Internet Message Format"">18</a>]
Status: standard
Author/change controller:
IETF (mailto:[email protected])
Internet Engineering Task Force
Specification document(s):
<a href="./rfc2822">RFC 2822</a> [<a href="#ref-18" title=""Internet Message Format"">18</a>] (<a href="#section-3.6.6">section 3.6.6</a>)
Related information:
Contains the mailbox(es) to which the message has been resent.
Defined as standard by <a href="./rfc822">RFC 822</a>.
<span class="grey">G. Klyne, et al. Standards Track [Page 14]</span><span id="page-15" ></span>
<span class="grey"><a href="./rfc4021">RFC 4021</a> Mail and MIME Header Fields March 2005</span>
<span class="h4"><a class="selflink" id="section-2.1.18" href="#section-2.1.18">2.1.18</a>. Header Field: Resent-Cc</span>
Description:
Mailbox(es) to which message is cc'ed on resend
Applicable protocol: Mail [<a href="#ref-18" title=""Internet Message Format"">18</a>]
Status: standard
Author/change controller:
IETF (mailto:[email protected])
Internet Engineering Task Force
Specification document(s):
<a href="./rfc2822">RFC 2822</a> [<a href="#ref-18" title=""Internet Message Format"">18</a>] (<a href="#section-3.6.6">section 3.6.6</a>)
Related information:
Contains the mailbox(es) to which message is cc'ed on resend.
Defined as standard by <a href="./rfc822">RFC 822</a>.
<span class="h4"><a class="selflink" id="section-2.1.19" href="#section-2.1.19">2.1.19</a>. Header Field: Resent-Bcc</span>
Description:
Mailbox(es) to which message is bcc'ed on resend
Applicable protocol: Mail [<a href="#ref-18" title=""Internet Message Format"">18</a>]
Status: standard
Author/change controller:
IETF (mailto:[email protected])
Internet Engineering Task Force
Specification document(s):
<a href="./rfc2822">RFC 2822</a> [<a href="#ref-18" title=""Internet Message Format"">18</a>] (<a href="#section-3.6.6">section 3.6.6</a>)
Related information:
Contains the mailbox(es) to which message is bcc'ed on resend.
Defined as standard by <a href="./rfc822">RFC 822</a>.
<span class="grey">G. Klyne, et al. Standards Track [Page 15]</span><span id="page-16" ></span>
<span class="grey"><a href="./rfc4021">RFC 4021</a> Mail and MIME Header Fields March 2005</span>
<span class="h4"><a class="selflink" id="section-2.1.20" href="#section-2.1.20">2.1.20</a>. Header Field: Resent-Reply-To</span>
Description:
Resent reply-to
Applicable protocol: Mail [<a href="#ref-18" title=""Internet Message Format"">18</a>]
Status: obsolete
Author/change controller:
IETF (mailto:[email protected])
Internet Engineering Task Force
Specification document(s):
<a href="./rfc2822">RFC 2822</a> [<a href="#ref-18" title=""Internet Message Format"">18</a>]
Related information:
Resent Reply-to. Defined by <a href="./rfc822">RFC 822</a>, obsoleted by <a href="./rfc2822">RFC 2822</a>.
<span class="h4"><a class="selflink" id="section-2.1.21" href="#section-2.1.21">2.1.21</a>. Header Field: Resent-Message-ID</span>
Description:
Message identifier for resent message
Applicable protocol: Mail [<a href="#ref-18" title=""Internet Message Format"">18</a>]
Status: standard
Author/change controller:
IETF (mailto:[email protected])
Internet Engineering Task Force
Specification document(s):
<a href="./rfc2822">RFC 2822</a> [<a href="#ref-18" title=""Internet Message Format"">18</a>] (<a href="#section-3.6.6">section 3.6.6</a>)
Related information:
Contains a message identifier for a resent message. Defined as
standard by <a href="./rfc822">RFC 822</a>.
<span class="grey">G. Klyne, et al. Standards Track [Page 16]</span><span id="page-17" ></span>
<span class="grey"><a href="./rfc4021">RFC 4021</a> Mail and MIME Header Fields March 2005</span>
<span class="h4"><a class="selflink" id="section-2.1.22" href="#section-2.1.22">2.1.22</a>. Header Field: Return-Path</span>
Description:
Message return path
Applicable protocol: Mail [<a href="#ref-18" title=""Internet Message Format"">18</a>]
Status: standard
Author/change controller:
IETF (mailto:[email protected])
Internet Engineering Task Force
Specification document(s):
<a href="./rfc2822">RFC 2822</a> [<a href="#ref-18" title=""Internet Message Format"">18</a>] (<a href="#section-3.6.7">section 3.6.7</a>)
Related information:
Return path for message response diagnostics. See also <a href="./rfc2821">RFC 2821</a>
[<a href="#ref-17" title=""Simple Mail Transfer Protocol"">17</a>]. Defined as standard by <a href="./rfc822">RFC 822</a>.
<span class="h4"><a class="selflink" id="section-2.1.23" href="#section-2.1.23">2.1.23</a>. Header Field: Received</span>
Description:
Mail transfer trace information
Applicable protocol: Mail [<a href="#ref-18" title=""Internet Message Format"">18</a>]
Status: standard
Author/change controller:
IETF (mailto:[email protected])
Internet Engineering Task Force
Specification document(s):
<a href="./rfc2822">RFC 2822</a> [<a href="#ref-18" title=""Internet Message Format"">18</a>] (<a href="#section-3.6.7">section 3.6.7</a>)
Related information:
Contains information about receipt of the current message by a
mail transfer agent on the transfer path. See also <a href="./rfc2821">RFC 2821</a> [<a href="#ref-17" title=""Simple Mail Transfer Protocol"">17</a>].
Defined as standard by <a href="./rfc822">RFC 822</a>.
<span class="grey">G. Klyne, et al. Standards Track [Page 17]</span><span id="page-18" ></span>
<span class="grey"><a href="./rfc4021">RFC 4021</a> Mail and MIME Header Fields March 2005</span>
<span class="h4"><a class="selflink" id="section-2.1.24" href="#section-2.1.24">2.1.24</a>. Header Field: Encrypted</span>
Description:
Message encryption information
Applicable protocol: Mail [<a href="#ref-18" title=""Internet Message Format"">18</a>]
Status: obsolete
Author/change controller:
IETF (mailto:[email protected])
Internet Engineering Task Force
Specification document(s):
<a href="./rfc822">RFC 822</a> [<a href="#ref-2" title=""Standard for the format of ARPA Internet text messages"">2</a>]
Related information:
Defined by <a href="./rfc822">RFC 822</a>, but was found to be inadequately specified,
was not widely implemented, and was removed in <a href="./rfc2822">RFC 2822</a>. Current
practice is to use separate encryption, such as S/MIME or OpenPGP,
possibly in conjunction with <a href="./rfc1847">RFC 1847</a> MIME security multiparts.
<span class="h4"><a class="selflink" id="section-2.1.25" href="#section-2.1.25">2.1.25</a>. Header Field: Disposition-Notification-To</span>
Description:
Mailbox for sending disposition notification
Applicable protocol: Mail [<a href="#ref-18" title=""Internet Message Format"">18</a>]
Status: standards-track
Author/change controller:
IETF (mailto:[email protected])
Internet Engineering Task Force
Specification document(s):
<a href="./rfc2298">RFC 2298</a> [<a href="#ref-12" title=""Message Disposition Notification"">12</a>]
Related information:
Indicates that the sender wants a disposition notification when
this message is received (read, processed, etc.) by its
recipients.
<span class="grey">G. Klyne, et al. Standards Track [Page 18]</span><span id="page-19" ></span>
<span class="grey"><a href="./rfc4021">RFC 4021</a> Mail and MIME Header Fields March 2005</span>
<span class="h4"><a class="selflink" id="section-2.1.26" href="#section-2.1.26">2.1.26</a>. Header Field: Disposition-Notification-Options</span>
Description:
Disposition notification options
Applicable protocol: Mail [<a href="#ref-18" title=""Internet Message Format"">18</a>]
Status: standards-track
Author/change controller:
IETF (mailto:[email protected])
Internet Engineering Task Force
Specification document(s):
<a href="./rfc2298">RFC 2298</a> [<a href="#ref-12" title=""Message Disposition Notification"">12</a>]
Related information:
For optional modifiers on disposition notification requests.
<span class="h4"><a class="selflink" id="section-2.1.27" href="#section-2.1.27">2.1.27</a>. Header Field: Accept-Language</span>
Description:
Language(s) for auto-responses
Applicable protocol: Mail [<a href="#ref-18" title=""Internet Message Format"">18</a>]
Status: standards-track
Author/change controller:
IETF (mailto:[email protected])
Internet Engineering Task Force
Specification document(s):
<a href="./rfc3282">RFC 3282</a> [<a href="#ref-21" title=""Content Language Headers"">21</a>]
Related information:
Indicates a language that the message sender requests to be used
for responses. Accept-language was not designed for email but has
been considered 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; and determining what character set encoding
should be used.
<span class="grey">G. Klyne, et al. Standards Track [Page 19]</span><span id="page-20" ></span>
<span class="grey"><a href="./rfc4021">RFC 4021</a> Mail and MIME Header Fields March 2005</span>
<span class="h4"><a class="selflink" id="section-2.1.28" href="#section-2.1.28">2.1.28</a>. Header Field: Original-Message-ID</span>
Description:
Original message identifier
Applicable protocol: Mail [<a href="#ref-18" title=""Internet Message Format"">18</a>]
Status: standards-track
Author/change controller:
IETF (mailto:[email protected])
Internet Engineering Task Force
Specification document(s):
<a href="./rfc3297">RFC 3297</a> [<a href="#ref-22" title=""Content Negotiation for Messaging Services based on Email"">22</a>]
Related information:
Original message identifier used with resend of message with
alternative content format; identifies the original message data
to which it corresponds.
<span class="h4"><a class="selflink" id="section-2.1.29" href="#section-2.1.29">2.1.29</a>. Header Field: PICS-Label</span>
Description:
PICS rating label
Applicable protocol: Mail [<a href="#ref-18" title=""Internet Message Format"">18</a>]
Status: standard
Author/change controller:
W3C (mailto:[email protected])
World Wide Web Consortium
Specification document(s):
PICS-labels [<a href="#ref-24" title=""PICS Label Distribution Label Syntax and Communication Protocols"">24</a>]
Related information:
Ratings label to control selection (filtering) of messages
according to the PICS protocol. Specified for general use with
<a href="./rfc822">RFC 822</a> message format, with HTTP-specific extensions.
<span class="grey">G. Klyne, et al. Standards Track [Page 20]</span><span id="page-21" ></span>
<span class="grey"><a href="./rfc4021">RFC 4021</a> Mail and MIME Header Fields March 2005</span>
<span class="h4"><a class="selflink" id="section-2.1.30" href="#section-2.1.30">2.1.30</a>. Header Field: Encoding</span>
Description:
Message encoding and other information
Applicable protocol: Mail [<a href="#ref-18" title=""Internet Message Format"">18</a>]
Status: experimental
Author/change controller:
Albert K. Costanzo (mailto:[email protected])
AKC Consulting Inc.
Specification document(s):
<a href="./rfc1505">RFC 1505</a> [<a href="#ref-4" title=""Encoding Header Field for Internet Messages"">4</a>]
Related information:
Used in several different ways by different mail systems. Some
use it for a kind of content-type information, some for encoding
and length information, some for a kind of boundary information,
and some in other ways.
<span class="h4"><a class="selflink" id="section-2.1.31" href="#section-2.1.31">2.1.31</a>. Header Field: List-Archive</span>
Description:
URL of mailing list archive
Applicable protocol: Mail [<a href="#ref-18" title=""Internet Message Format"">18</a>]
Status: standards-track
Author/change controller:
IETF (mailto:[email protected])
Internet Engineering Task Force
Specification document(s):
<a href="./rfc2369">RFC 2369</a> [<a href="#ref-13" title=""The Use of URLs as Meta-Syntax for Core Mail List Commands and their Transport through Message Header Fields"">13</a>]
Related information:
Contains the URL to use to browse the archives of the mailing list
from which this message was relayed.
<span class="grey">G. Klyne, et al. Standards Track [Page 21]</span><span id="page-22" ></span>
<span class="grey"><a href="./rfc4021">RFC 4021</a> Mail and MIME Header Fields March 2005</span>
<span class="h4"><a class="selflink" id="section-2.1.32" href="#section-2.1.32">2.1.32</a>. Header Field: List-Help</span>
Description:
URL for mailing list information
Applicable protocol: Mail [<a href="#ref-18" title=""Internet Message Format"">18</a>]
Status: standards-track
Author/change controller:
IETF (mailto:[email protected])
Internet Engineering Task Force
Specification document(s):
<a href="./rfc2369">RFC 2369</a> [<a href="#ref-13" title=""The Use of URLs as Meta-Syntax for Core Mail List Commands and their Transport through Message Header Fields"">13</a>]
Related information:
Contains the URL to use to get information about the mailing list
from which this message was relayed.
<span class="h4"><a class="selflink" id="section-2.1.33" href="#section-2.1.33">2.1.33</a>. Header Field: List-ID</span>
Description:
Mailing list identifier
Applicable protocol: Mail [<a href="#ref-18" title=""Internet Message Format"">18</a>]
Status: standards-track
Author/change controller:
IETF (mailto:[email protected])
Internet Engineering Task Force
Specification document(s):
<a href="./rfc2919">RFC 2919</a> [<a href="#ref-20" title=""List-Id: A Structured Field and Namespace for the Identification of Mailing Lists"">20</a>]
Related information:
Stores an identification of the mailing list through which this
message was distributed.
<span class="grey">G. Klyne, et al. Standards Track [Page 22]</span><span id="page-23" ></span>
<span class="grey"><a href="./rfc4021">RFC 4021</a> Mail and MIME Header Fields March 2005</span>
<span class="h4"><a class="selflink" id="section-2.1.34" href="#section-2.1.34">2.1.34</a>. Header Field: List-Owner</span>
Description:
URL for mailing list owner's mailbox
Applicable protocol: Mail [<a href="#ref-18" title=""Internet Message Format"">18</a>]
Status: standards-track
Author/change controller:
IETF (mailto:[email protected])
Internet Engineering Task Force
Specification document(s):
<a href="./rfc2369">RFC 2369</a> [<a href="#ref-13" title=""The Use of URLs as Meta-Syntax for Core Mail List Commands and their Transport through Message Header Fields"">13</a>]
Related information:
Contains the URL to send e-mail to the owner of the mailing list
from which this message was relayed.
<span class="h4"><a class="selflink" id="section-2.1.35" href="#section-2.1.35">2.1.35</a>. Header Field: List-Post</span>
Description:
URL for mailing list posting
Applicable protocol: Mail [<a href="#ref-18" title=""Internet Message Format"">18</a>]
Status: standards-track
Author/change controller:
IETF (mailto:[email protected])
Internet Engineering Task Force
Specification document(s):
<a href="./rfc2369">RFC 2369</a> [<a href="#ref-13" title=""The Use of URLs as Meta-Syntax for Core Mail List Commands and their Transport through Message Header Fields"">13</a>]
Related information:
Contains the URL to use to send contributions to the mailing list
from which this message was relayed.
<span class="grey">G. Klyne, et al. Standards Track [Page 23]</span><span id="page-24" ></span>
<span class="grey"><a href="./rfc4021">RFC 4021</a> Mail and MIME Header Fields March 2005</span>
<span class="h4"><a class="selflink" id="section-2.1.36" href="#section-2.1.36">2.1.36</a>. Header Field: List-Subscribe</span>
Description:
URL for mailing list subscription
Applicable protocol: Mail [<a href="#ref-18" title=""Internet Message Format"">18</a>]
Status: standards-track
Author/change controller:
IETF (mailto:[email protected])
Internet Engineering Task Force
Specification document(s):
<a href="./rfc2369">RFC 2369</a> [<a href="#ref-13" title=""The Use of URLs as Meta-Syntax for Core Mail List Commands and their Transport through Message Header Fields"">13</a>]
Related information:
Contains the URL to use to get a subscription to the mailing list
from which this message was relayed.
<span class="h4"><a class="selflink" id="section-2.1.37" href="#section-2.1.37">2.1.37</a>. Header Field: List-Unsubscribe</span>
Description:
URL for mailing list unsubscription
Applicable protocol: Mail [<a href="#ref-18" title=""Internet Message Format"">18</a>]
Status: standards-track
Author/change controller:
IETF (mailto:[email protected])
Internet Engineering Task Force
Specification document(s):
<a href="./rfc2369">RFC 2369</a> [<a href="#ref-13" title=""The Use of URLs as Meta-Syntax for Core Mail List Commands and their Transport through Message Header Fields"">13</a>]
Related information:
Contains the URL to use to unsubscribe the mailing list from which
this message was relayed.
<span class="grey">G. Klyne, et al. Standards Track [Page 24]</span><span id="page-25" ></span>
<span class="grey"><a href="./rfc4021">RFC 4021</a> Mail and MIME Header Fields March 2005</span>
<span class="h4"><a class="selflink" id="section-2.1.38" href="#section-2.1.38">2.1.38</a>. Header Field: Message-Context</span>
Description:
Type or context of message
Applicable protocol: Mail [<a href="#ref-18" title=""Internet Message Format"">18</a>]
Status: standards-track
Author/change controller:
IETF (mailto:[email protected])
Internet Engineering Task Force
Specification document(s):
<a href="./rfc3458">RFC 3458</a> [<a href="#ref-23" title=""Message Context for Internet Mail"">23</a>]
Related information:
Provides information about the context and presentation
characteristics of a message. Can have the values 'voice-
message', 'fax-message', 'pager-message', 'multimedia-message',
'text-message', or 'none'.
<span class="h4"><a class="selflink" id="section-2.1.39" href="#section-2.1.39">2.1.39</a>. Header Field: DL-Expansion-History</span>
Description:
Trace of distribution lists passed
Applicable protocol: Mail [<a href="#ref-18" title=""Internet Message Format"">18</a>]
Status: standards-track
Author/change controller:
IETF (mailto:[email protected])
Internet Engineering Task Force
Specification document(s):
<a href="./rfc2156">RFC 2156</a> [<a href="#ref-10" title=""MIXER (Mime Internet X.400 Enhanced Relay): Mapping between X.400 and RFC 822/MIME"">10</a>]
Related information:
Trace of distribution lists passed. (MIXER X.400 mapping; not for
general use.)
<span class="grey">G. Klyne, et al. Standards Track [Page 25]</span><span id="page-26" ></span>
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<span class="h4"><a class="selflink" id="section-2.1.40" href="#section-2.1.40">2.1.40</a>. Header Field: Alternate-Recipient</span>
Description:
Controls forwarding to alternate recipients
Applicable protocol: Mail [<a href="#ref-18" title=""Internet Message Format"">18</a>]
Status: standards-track
Author/change controller:
IETF (mailto:[email protected])
Internet Engineering Task Force
Specification document(s):
<a href="./rfc2156">RFC 2156</a> [<a href="#ref-10" title=""MIXER (Mime Internet X.400 Enhanced Relay): Mapping between X.400 and RFC 822/MIME"">10</a>]
Related information:
Controls whether this message may be forwarded to an alternate
recipient, such as a postmaster, if delivery to the intended
recipient is not possible. Default: Allowed. <a href="./rfc2156">RFC 2156</a> (MIXER),
not for general use.
<span class="h4"><a class="selflink" id="section-2.1.41" href="#section-2.1.41">2.1.41</a>. Header Field: Original-Encoded-Information-Types</span>
Description:
Body part types in message
Applicable protocol: Mail [<a href="#ref-18" title=""Internet Message Format"">18</a>]
Status: standards-track
Author/change controller:
IETF (mailto:[email protected])
Internet Engineering Task Force
Specification document(s):
<a href="./rfc2156">RFC 2156</a> [<a href="#ref-10" title=""MIXER (Mime Internet X.400 Enhanced Relay): Mapping between X.400 and RFC 822/MIME"">10</a>]
Related information:
Which body part types occur in this message. <a href="./rfc2156">RFC 2156</a> (MIXER);
not for general use.
<span class="grey">G. Klyne, et al. Standards Track [Page 26]</span><span id="page-27" ></span>
<span class="grey"><a href="./rfc4021">RFC 4021</a> Mail and MIME Header Fields March 2005</span>
<span class="h4"><a class="selflink" id="section-2.1.42" href="#section-2.1.42">2.1.42</a>. Header Field: Content-Return</span>
Description:
Return content on non-delivery?
Applicable protocol: Mail [<a href="#ref-18" title=""Internet Message Format"">18</a>]
Status: obsolete
Author/change controller:
IETF (mailto:[email protected])
Internet Engineering Task Force
Specification document(s):
<a href="./rfc1327">RFC 1327</a> [<a href="#ref-3" title=""Mapping between X.400(1988) / ISO 10021 and RFC 822"">3</a>]
Related information:
Indicates whether the content of a message is to be returned with
non-delivery notifications. Introduced by <a href="./rfc1327">RFC 1327</a> and
subsequently changed by <a href="./rfc2156">RFC 2156</a> to avoid confusion with MIME
defined fields.
<span class="h4"><a class="selflink" id="section-2.1.43" href="#section-2.1.43">2.1.43</a>. Header Field: Generate-Delivery-Report</span>
Description:
Request delivery report generation
Applicable protocol: Mail [<a href="#ref-18" title=""Internet Message Format"">18</a>]
Status: standards-track
Author/change controller:
IETF (mailto:[email protected])
Internet Engineering Task Force
Specification document(s):
<a href="./rfc2156">RFC 2156</a> [<a href="#ref-10" title=""MIXER (Mime Internet X.400 Enhanced Relay): Mapping between X.400 and RFC 822/MIME"">10</a>]
Related information:
Indicates whether a delivery report is wanted at successful
delivery. Default is not to generate such a report. <a href="./rfc2156">RFC 2156</a>
(MIXER); not for general use.
<span class="grey">G. Klyne, et al. Standards Track [Page 27]</span><span id="page-28" ></span>
<span class="grey"><a href="./rfc4021">RFC 4021</a> Mail and MIME Header Fields March 2005</span>
<span class="h4"><a class="selflink" id="section-2.1.44" href="#section-2.1.44">2.1.44</a>. Header Field: Prevent-NonDelivery-Report</span>
Description:
Non-delivery report required?
Applicable protocol: Mail [<a href="#ref-18" title=""Internet Message Format"">18</a>]
Status: standards-track
Author/change controller:
IETF (mailto:[email protected])
Internet Engineering Task Force
Specification document(s):
<a href="./rfc2156">RFC 2156</a> [<a href="#ref-10" title=""MIXER (Mime Internet X.400 Enhanced Relay): Mapping between X.400 and RFC 822/MIME"">10</a>]
Related information:
Indicates whether a non-delivery report is wanted on delivery
error. Default is to generate such a report. <a href="./rfc2156">RFC 2156</a> (MIXER);
not for general use.
<span class="h4"><a class="selflink" id="section-2.1.45" href="#section-2.1.45">2.1.45</a>. Header Field: Obsoletes</span>
Description:
Reference message to be replaced
Applicable protocol: Mail [<a href="#ref-18" title=""Internet Message Format"">18</a>]
Status: obsolete
Author/change controller:
IETF (mailto:[email protected])
Internet Engineering Task Force
Specification document(s):
<a href="./rfc1327">RFC 1327</a> [<a href="#ref-3" title=""Mapping between X.400(1988) / ISO 10021 and RFC 822"">3</a>]
Related information:
Reference to a previous message being corrected and replaced.
Compare to 'Supersedes:',f used in Usenet News. Introduced by <a href="./rfc1327">RFC</a>
<a href="./rfc1327">1327</a> and subsequently renamed by <a href="./rfc2156">RFC 2156</a> to 'Supersedes'.
<span class="grey">G. Klyne, et al. Standards Track [Page 28]</span><span id="page-29" ></span>
<span class="grey"><a href="./rfc4021">RFC 4021</a> Mail and MIME Header Fields March 2005</span>
<span class="h4"><a class="selflink" id="section-2.1.46" href="#section-2.1.46">2.1.46</a>. Header Field: Supersedes</span>
Description:
Reference message to be replaced
Applicable protocol: Mail [<a href="#ref-18" title=""Internet Message Format"">18</a>]
Status: standards-track
Author/change controller:
IETF (mailto:[email protected])
Internet Engineering Task Force
Specification document(s):
<a href="./rfc2156">RFC 2156</a> [<a href="#ref-10" title=""MIXER (Mime Internet X.400 Enhanced Relay): Mapping between X.400 and RFC 822/MIME"">10</a>]
Related information:
Reference to a previous message being corrected and replaced.
Renamed version of obsolete 'Obsoletes' header field. <a href="./rfc2156">RFC 2156</a>
(MIXER); not for general use.
<span class="h4"><a class="selflink" id="section-2.1.47" href="#section-2.1.47">2.1.47</a>. Header Field: Content-Identifier</span>
Description:
Message content identifier
Applicable protocol: Mail [<a href="#ref-18" title=""Internet Message Format"">18</a>]
Status: obsolete
Author/change controller:
IETF (mailto:[email protected])
Internet Engineering Task Force
Specification document(s):
<a href="./rfc1327">RFC 1327</a> [<a href="#ref-3" title=""Mapping between X.400(1988) / ISO 10021 and RFC 822"">3</a>]
Related information:
A text string that identifies the content of a message.
Introduced by <a href="./rfc1327">RFC 1327</a> and subsequently changed by <a href="./rfc2156">RFC 2156</a> to
avoid confusion with MIME defined fields. Gateways that reverse
map may support the old field.
<span class="grey">G. Klyne, et al. Standards Track [Page 29]</span><span id="page-30" ></span>
<span class="grey"><a href="./rfc4021">RFC 4021</a> Mail and MIME Header Fields March 2005</span>
<span class="h4"><a class="selflink" id="section-2.1.48" href="#section-2.1.48">2.1.48</a>. Header Field: Delivery-Date</span>
Description:
Message delivery time
Applicable protocol: Mail [<a href="#ref-18" title=""Internet Message Format"">18</a>]
Status: standards-track
Author/change controller:
IETF (mailto:[email protected])
Internet Engineering Task Force
Specification document(s):
<a href="./rfc2156">RFC 2156</a> [<a href="#ref-10" title=""MIXER (Mime Internet X.400 Enhanced Relay): Mapping between X.400 and RFC 822/MIME"">10</a>]
Related information:
The time when a message was delivered to its recipient. <a href="./rfc2156">RFC 2156</a>
(MIXER); not for general use.
<span class="h4"><a class="selflink" id="section-2.1.49" href="#section-2.1.49">2.1.49</a>. Header Field: Expiry-Date</span>
Description:
Message expiry time
Applicable protocol: Mail [<a href="#ref-18" title=""Internet Message Format"">18</a>]
Status: obsolete
Author/change controller:
IETF (mailto:[email protected])
Internet Engineering Task Force
Specification document(s):
<a href="./rfc1327">RFC 1327</a> [<a href="#ref-3" title=""Mapping between X.400(1988) / ISO 10021 and RFC 822"">3</a>]
Related information:
Time at which a message loses its validity. Introduced by <a href="./rfc1327">RFC</a>
<a href="./rfc1327">1327</a> and subsequently changed by <a href="./rfc2156">RFC 2156</a> to 'Expires:'.
<span class="grey">G. Klyne, et al. Standards Track [Page 30]</span><span id="page-31" ></span>
<span class="grey"><a href="./rfc4021">RFC 4021</a> Mail and MIME Header Fields March 2005</span>
<span class="h4"><a class="selflink" id="section-2.1.50" href="#section-2.1.50">2.1.50</a>. Header Field: Expires</span>
Description:
Message expiry time
Applicable protocol: Mail [<a href="#ref-18" title=""Internet Message Format"">18</a>]
Status: standards-track
Author/change controller:
IETF (mailto:[email protected])
Internet Engineering Task Force
Specification document(s):
<a href="./rfc2156">RFC 2156</a> [<a href="#ref-10" title=""MIXER (Mime Internet X.400 Enhanced Relay): Mapping between X.400 and RFC 822/MIME"">10</a>]
Related information:
Time at which a message loses its validity. Renamed version of
obsolete Expiry-Date header field. <a href="./rfc2156">RFC 2156</a> (MIXER), not for
general use.
<span class="h4"><a class="selflink" id="section-2.1.51" href="#section-2.1.51">2.1.51</a>. Header Field: Reply-By</span>
Description:
Time by which a reply is requested
Applicable protocol: Mail [<a href="#ref-18" title=""Internet Message Format"">18</a>]
Status: standards-track
Author/change controller:
IETF (mailto:[email protected])
Internet Engineering Task Force
Specification document(s):
<a href="./rfc2156">RFC 2156</a> [<a href="#ref-10" title=""MIXER (Mime Internet X.400 Enhanced Relay): Mapping between X.400 and RFC 822/MIME"">10</a>]
Related information:
Latest time by which a reply is requested (not demanded). <a href="./rfc2156">RFC</a>
<a href="./rfc2156">2156</a> (MIXER); not for general use.
<span class="grey">G. Klyne, et al. Standards Track [Page 31]</span><span id="page-32" ></span>
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<span class="h4"><a class="selflink" id="section-2.1.52" href="#section-2.1.52">2.1.52</a>. Header Field: Importance</span>
Description:
Message importance
Applicable protocol: Mail [<a href="#ref-18" title=""Internet Message Format"">18</a>]
Status: standards-track
Author/change controller:
IETF (mailto:[email protected])
Internet Engineering Task Force
Specification document(s):
<a href="./rfc2156">RFC 2156</a> [<a href="#ref-10" title=""MIXER (Mime Internet X.400 Enhanced Relay): Mapping between X.400 and RFC 822/MIME"">10</a>]
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 <a href="./rfc2156">RFC 2156</a> (MIXER) [<a href="#ref-10" title=""MIXER (Mime Internet X.400 Enhanced Relay): Mapping between X.400 and RFC 822/MIME"">10</a>]
and <a href="./rfc3801">RFC 3801</a> (VPIM) [<a href="#ref-14" title=""Voice Profile for Internet Mail - version 2 (VPIMv2)"">14</a>].
<span class="h4"><a class="selflink" id="section-2.1.53" href="#section-2.1.53">2.1.53</a>. Header Field: Incomplete-Copy</span>
Description:
Body parts are missing
Applicable protocol: Mail [<a href="#ref-18" title=""Internet Message Format"">18</a>]
Status: standards-track
Author/change controller:
IETF (mailto:[email protected])
Internet Engineering Task Force
Specification document(s):
<a href="./rfc2156">RFC 2156</a> [<a href="#ref-10" title=""MIXER (Mime Internet X.400 Enhanced Relay): Mapping between X.400 and RFC 822/MIME"">10</a>]
Related information:
Body parts are missing. <a href="./rfc2156">RFC 2156</a> (MIXER); not for general use.
<span class="grey">G. Klyne, et al. Standards Track [Page 32]</span><span id="page-33" ></span>
<span class="grey"><a href="./rfc4021">RFC 4021</a> Mail and MIME Header Fields March 2005</span>
<span class="h4"><a class="selflink" id="section-2.1.54" href="#section-2.1.54">2.1.54</a>. Header Field: Priority</span>
Description:
Message priority
Applicable protocol: Mail [<a href="#ref-18" title=""Internet Message Format"">18</a>]
Status: standards-track
Author/change controller:
IETF (mailto:[email protected])
Internet Engineering Task Force
Specification document(s):
<a href="./rfc2156">RFC 2156</a> [<a href="#ref-10" title=""MIXER (Mime Internet X.400 Enhanced Relay): Mapping between X.400 and RFC 822/MIME"">10</a>]
Related information:
Can be 'normal', 'urgent', or 'non-urgent' and can influence
transmission speed and delivery. <a href="./rfc2156">RFC 2156</a> (MIXER); not for
general use.
<span class="h4"><a class="selflink" id="section-2.1.55" href="#section-2.1.55">2.1.55</a>. Header Field: Sensitivity</span>
Description:
Message content sensitivity
Applicable protocol: Mail [<a href="#ref-18" title=""Internet Message Format"">18</a>]
Status: standards-track
Author/change controller:
IETF (mailto:[email protected])
Internet Engineering Task Force
Specification document(s):
<a href="./rfc2156">RFC 2156</a> [<a href="#ref-10" title=""MIXER (Mime Internet X.400 Enhanced Relay): Mapping between X.400 and RFC 822/MIME"">10</a>]
Related information:
How sensitive it is to disclose this message to people other than
the specified recipients. Values: Personal, private, and company
confidential. The absence of this header field in messages
gatewayed from X.400 indicates that the message is not sensitive.
Proposed for use with <a href="./rfc2156">RFC 2156</a> (MIXER) [<a href="#ref-10" title=""MIXER (Mime Internet X.400 Enhanced Relay): Mapping between X.400 and RFC 822/MIME"">10</a>] and <a href="./rfc3801">RFC 3801</a> (VPIM)
[<a href="#ref-14" title=""Voice Profile for Internet Mail - version 2 (VPIMv2)"">14</a>].
<span class="grey">G. Klyne, et al. Standards Track [Page 33]</span><span id="page-34" ></span>
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<span class="h4"><a class="selflink" id="section-2.1.56" href="#section-2.1.56">2.1.56</a>. Header Field: Language</span>
Description:
X.400 message content language
Applicable protocol: Mail [<a href="#ref-18" title=""Internet Message Format"">18</a>]
Status: standards-track
Author/change controller:
IETF (mailto:[email protected])
Internet Engineering Task Force
Specification document(s):
<a href="./rfc2156">RFC 2156</a> [<a href="#ref-10" title=""MIXER (Mime Internet X.400 Enhanced Relay): Mapping between X.400 and RFC 822/MIME"">10</a>]
Related information:
Can include a code for the natural language used in a message;
e.g., 'en' for English. See also 'Content-Language'. <a href="./rfc2156">RFC 2156</a>
(MIXER); not for general use.
<span class="h4"><a class="selflink" id="section-2.1.57" href="#section-2.1.57">2.1.57</a>. Header Field: Conversion</span>
Description:
Conversion allowed?
Applicable protocol: Mail [<a href="#ref-18" title=""Internet Message Format"">18</a>]
Status: standards-track
Author/change controller:
IETF (mailto:[email protected])
Internet Engineering Task Force
Specification document(s):
<a href="./rfc2156">RFC 2156</a> [<a href="#ref-10" title=""MIXER (Mime Internet X.400 Enhanced Relay): Mapping between X.400 and RFC 822/MIME"">10</a>]
Related information:
The body of this message may not be converted from one character
set to another. Values: prohibited and allowed. <a href="./rfc2156">RFC 2156</a>
(MIXER); not for general use.
<span class="grey">G. Klyne, et al. Standards Track [Page 34]</span><span id="page-35" ></span>
<span class="grey"><a href="./rfc4021">RFC 4021</a> Mail and MIME Header Fields March 2005</span>
<span class="h4"><a class="selflink" id="section-2.1.58" href="#section-2.1.58">2.1.58</a>. Header Field: Conversion-With-Loss</span>
Description:
Lossy conversion allowed?
Applicable protocol: Mail [<a href="#ref-18" title=""Internet Message Format"">18</a>]
Status: standards-track
Author/change controller:
IETF (mailto:[email protected])
Internet Engineering Task Force
Specification document(s):
<a href="./rfc2156">RFC 2156</a> [<a href="#ref-10" title=""MIXER (Mime Internet X.400 Enhanced Relay): Mapping between X.400 and RFC 822/MIME"">10</a>]
Related information:
The body of this message may not be converted from one character
set to another if information will be lost. Values: prohibited
and allowed. <a href="./rfc2156">RFC 2156</a> (MIXER); not for general use.
<span class="h4"><a class="selflink" id="section-2.1.59" href="#section-2.1.59">2.1.59</a>. Header Field: Message-Type</span>
Description:
Message type: delivery report?
Applicable protocol: Mail [<a href="#ref-18" title=""Internet Message Format"">18</a>]
Status: standards-track
Author/change controller:
IETF (mailto:[email protected])
Internet Engineering Task Force
Specification document(s):
<a href="./rfc2156">RFC 2156</a> [<a href="#ref-10" title=""MIXER (Mime Internet X.400 Enhanced Relay): Mapping between X.400 and RFC 822/MIME"">10</a>]
Related information:
Only used with the value 'Delivery Report' to indicate that this
is a delivery report gatewayed from X.400. <a href="./rfc2156">RFC 2156</a> (MIXER); not
for general use.
<span class="grey">G. Klyne, et al. Standards Track [Page 35]</span><span id="page-36" ></span>
<span class="grey"><a href="./rfc4021">RFC 4021</a> Mail and MIME Header Fields March 2005</span>
<span class="h4"><a class="selflink" id="section-2.1.60" href="#section-2.1.60">2.1.60</a>. Header Field: Autosubmitted</span>
Description:
Automatically submitted indicator
Applicable protocol: Mail [<a href="#ref-18" title=""Internet Message Format"">18</a>]
Status: standards-track
Author/change controller:
IETF (mailto:[email protected])
Internet Engineering Task Force
Specification document(s):
<a href="./rfc2156">RFC 2156</a> [<a href="#ref-10" title=""MIXER (Mime Internet X.400 Enhanced Relay): Mapping between X.400 and RFC 822/MIME"">10</a>]
Related information:
Has been automatically submitted. <a href="./rfc2156">RFC 2156</a> (MIXER); not for
general use.
<span class="h4"><a class="selflink" id="section-2.1.61" href="#section-2.1.61">2.1.61</a>. Header Field: Autoforwarded</span>
Description:
Automatically forwarded indicator
Applicable protocol: Mail [<a href="#ref-18" title=""Internet Message Format"">18</a>]
Status: standards-track
Author/change controller:
IETF (mailto:[email protected])
Internet Engineering Task Force
Specification document(s):
<a href="./rfc2156">RFC 2156</a> [<a href="#ref-10" title=""MIXER (Mime Internet X.400 Enhanced Relay): Mapping between X.400 and RFC 822/MIME"">10</a>]
Related information:
Has been automatically forwarded. <a href="./rfc2156">RFC 2156</a> (MIXER), not for
general use.
<span class="grey">G. Klyne, et al. Standards Track [Page 36]</span><span id="page-37" ></span>
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<span class="h4"><a class="selflink" id="section-2.1.62" href="#section-2.1.62">2.1.62</a>. Header Field: Discarded-X400-IPMS-Extensions</span>
Description:
X.400 IPM extensions discarded
Applicable protocol: Mail [<a href="#ref-18" title=""Internet Message Format"">18</a>]
Status: standards-track
Author/change controller:
IETF (mailto:[email protected])
Internet Engineering Task Force
Specification document(s):
<a href="./rfc2156">RFC 2156</a> [<a href="#ref-10" title=""MIXER (Mime Internet X.400 Enhanced Relay): Mapping between X.400 and RFC 822/MIME"">10</a>]
Related information:
Can be used in Internet mail to indicate X.400 IPM extensions that
could not be mapped to Internet mail format. <a href="./rfc2156">RFC 2156</a> (MIXER);
not for general use.
<span class="h4"><a class="selflink" id="section-2.1.63" href="#section-2.1.63">2.1.63</a>. Header Field: Discarded-X400-MTS-Extensions</span>
Description:
X.400 MTS extensions discarded
Applicable protocol: Mail [<a href="#ref-18" title=""Internet Message Format"">18</a>]
Status: standards-track
Author/change controller:
IETF (mailto:[email protected])
Internet Engineering Task Force
Specification document(s):
<a href="./rfc2156">RFC 2156</a> [<a href="#ref-10" title=""MIXER (Mime Internet X.400 Enhanced Relay): Mapping between X.400 and RFC 822/MIME"">10</a>]
Related information:
Can be used in Internet mail to indicate X.400 MTS extensions that
could not be mapped to Internet mail format. <a href="./rfc2156">RFC 2156</a> (MIXER);
not for general use.
<span class="grey">G. Klyne, et al. Standards Track [Page 37]</span><span id="page-38" ></span>
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<span class="h4"><a class="selflink" id="section-2.1.64" href="#section-2.1.64">2.1.64</a>. Header Field: Disclose-Recipients</span>
Description:
Disclose names of other recipients?
Applicable protocol: Mail [<a href="#ref-18" title=""Internet Message Format"">18</a>]
Status: standards-track
Author/change controller:
IETF (mailto:[email protected])
Internet Engineering Task Force
Specification document(s):
<a href="./rfc2156">RFC 2156</a> [<a href="#ref-10" title=""MIXER (Mime Internet X.400 Enhanced Relay): Mapping between X.400 and RFC 822/MIME"">10</a>]
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 done in Internet mail via the To:, cc:, and bcc:
header fields. Not for general use.
<span class="h4"><a class="selflink" id="section-2.1.65" href="#section-2.1.65">2.1.65</a>. Header Field: Deferred-Delivery</span>
Description:
Deferred delivery information
Applicable protocol: Mail [<a href="#ref-18" title=""Internet Message Format"">18</a>]
Status: standards-track
Author/change controller:
IETF (mailto:[email protected])
Internet Engineering Task Force
Specification document(s):
<a href="./rfc2156">RFC 2156</a> [<a href="#ref-10" title=""MIXER (Mime Internet X.400 Enhanced Relay): Mapping between X.400 and RFC 822/MIME"">10</a>]
Related information:
Provides information about deferred delivery service to the
recipient. <a href="./rfc2156">RFC 2156</a> (MIXER); not for general use.
<span class="grey">G. Klyne, et al. Standards Track [Page 38]</span><span id="page-39" ></span>
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<span class="h4"><a class="selflink" id="section-2.1.66" href="#section-2.1.66">2.1.66</a>. Header Field: Latest-Delivery-Time</span>
Description:
Latest delivery time requested
Applicable protocol: Mail [<a href="#ref-18" title=""Internet Message Format"">18</a>]
Status: standards-track
Author/change controller:
IETF (mailto:[email protected])
Internet Engineering Task Force
Specification document(s):
<a href="./rfc2156">RFC 2156</a> [<a href="#ref-10" title=""MIXER (Mime Internet X.400 Enhanced Relay): Mapping between X.400 and RFC 822/MIME"">10</a>]
Related information:
Provides the recipient with information about requested delivery
but will not be acted on by the SMTP infrastructure. <a href="./rfc2156">RFC 2156</a>
(MIXER); not for general use.
<span class="h4"><a class="selflink" id="section-2.1.67" href="#section-2.1.67">2.1.67</a>. Header Field: Originator-Return-Address</span>
Description:
Originator return address
Applicable protocol: Mail [<a href="#ref-18" title=""Internet Message Format"">18</a>]
Status: standards-track
Author/change controller:
IETF (mailto:[email protected])
Internet Engineering Task Force
Specification document(s):
<a href="./rfc2156">RFC 2156</a> [<a href="#ref-10" title=""MIXER (Mime Internet X.400 Enhanced Relay): Mapping between X.400 and RFC 822/MIME"">10</a>]
Related information:
Originator return address. <a href="./rfc2156">RFC 2156</a> (MIXER); not for general use.
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<span class="h4"><a class="selflink" id="section-2.1.68" href="#section-2.1.68">2.1.68</a>. Header Field: X400-Content-Identifier</span>
Description:
Message content identifier
Applicable protocol: Mail [<a href="#ref-18" title=""Internet Message Format"">18</a>]
Status: standards-track
Author/change controller:
IETF (mailto:[email protected])
Internet Engineering Task Force
Specification document(s):
<a href="./rfc2156">RFC 2156</a> [<a href="#ref-10" title=""MIXER (Mime Internet X.400 Enhanced Relay): Mapping between X.400 and RFC 822/MIME"">10</a>]
Related information:
A text string that identifies the content of a message. Renamed
version of obsolete Content-Identifier field. <a href="./rfc2156">RFC 2156</a> (MIXER);
not for general use.
<span class="h4"><a class="selflink" id="section-2.1.69" href="#section-2.1.69">2.1.69</a>. Header Field: X400-Content-Return</span>
Description:
Return content on non-delivery?
Applicable protocol: Mail [<a href="#ref-18" title=""Internet Message Format"">18</a>]
Status: standards-track
Author/change controller:
IETF (mailto:[email protected])
Internet Engineering Task Force
Specification document(s):
<a href="./rfc2156">RFC 2156</a> [<a href="#ref-10" title=""MIXER (Mime Internet X.400 Enhanced Relay): Mapping between X.400 and RFC 822/MIME"">10</a>]
Related information:
Indicates whether the content of a message is to be returned with
non-delivery notifications. Renamed version of obsolete Content-
Return field. <a href="./rfc2156">RFC 2156</a> (MIXER); not for general use.
<span class="grey">G. Klyne, et al. Standards Track [Page 40]</span><span id="page-41" ></span>
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<span class="h4"><a class="selflink" id="section-2.1.70" href="#section-2.1.70">2.1.70</a>. Header Field: X400-Content-Type</span>
Description:
X400 content type
Applicable protocol: Mail [<a href="#ref-18" title=""Internet Message Format"">18</a>]
Status: standards-track
Author/change controller:
IETF (mailto:[email protected])
Internet Engineering Task Force
Specification document(s):
<a href="./rfc2156">RFC 2156</a> [<a href="#ref-10" title=""MIXER (Mime Internet X.400 Enhanced Relay): Mapping between X.400 and RFC 822/MIME"">10</a>]
Related information:
X400 content type. <a href="./rfc2156">RFC 2156</a> (MIXER); not for general use.
<span class="h4"><a class="selflink" id="section-2.1.71" href="#section-2.1.71">2.1.71</a>. Header Field: X400-MTS-Identifier</span>
Description:
X400 MTS-Identifier
Applicable protocol: Mail [<a href="#ref-18" title=""Internet Message Format"">18</a>]
Status: standards-track
Author/change controller:
IETF (mailto:[email protected])
Internet Engineering Task Force
Specification document(s):
<a href="./rfc2156">RFC 2156</a> [<a href="#ref-10" title=""MIXER (Mime Internet X.400 Enhanced Relay): Mapping between X.400 and RFC 822/MIME"">10</a>]
Related information:
X400 MTS-Identifier. <a href="./rfc2156">RFC 2156</a> (MIXER); not for general use.
<span class="grey">G. Klyne, et al. Standards Track [Page 41]</span><span id="page-42" ></span>
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<span class="h4"><a class="selflink" id="section-2.1.72" href="#section-2.1.72">2.1.72</a>. Header Field: X400-Originator</span>
Description:
X400 Originator
Applicable protocol: Mail [<a href="#ref-18" title=""Internet Message Format"">18</a>]
Status: standards-track
Author/change controller:
IETF (mailto:[email protected])
Internet Engineering Task Force
Specification document(s):
<a href="./rfc2156">RFC 2156</a> [<a href="#ref-10" title=""MIXER (Mime Internet X.400 Enhanced Relay): Mapping between X.400 and RFC 822/MIME"">10</a>]
Related information:
X400 Originator. <a href="./rfc2156">RFC 2156</a> (MIXER); not for general use.
<span class="h4"><a class="selflink" id="section-2.1.73" href="#section-2.1.73">2.1.73</a>. Header Field: X400-Received</span>
Description:
X400 Received
Applicable protocol: Mail [<a href="#ref-18" title=""Internet Message Format"">18</a>]
Status: standards-track
Author/change controller:
IETF (mailto:[email protected])
Internet Engineering Task Force
Specification document(s):
<a href="./rfc2156">RFC 2156</a> [<a href="#ref-10" title=""MIXER (Mime Internet X.400 Enhanced Relay): Mapping between X.400 and RFC 822/MIME"">10</a>]
Related information:
X400 Received. <a href="./rfc2156">RFC 2156</a> (MIXER); not for general use.
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<span class="h4"><a class="selflink" id="section-2.1.74" href="#section-2.1.74">2.1.74</a>. Header Field: X400-Recipients</span>
Description:
X400 Recipients
Applicable protocol: Mail [<a href="#ref-18" title=""Internet Message Format"">18</a>]
Status: standards-track
Author/change controller:
IETF (mailto:[email protected])
Internet Engineering Task Force
Specification document(s):
<a href="./rfc2156">RFC 2156</a> [<a href="#ref-10" title=""MIXER (Mime Internet X.400 Enhanced Relay): Mapping between X.400 and RFC 822/MIME"">10</a>]
Related information:
X400 Recipients. <a href="./rfc2156">RFC 2156</a> (MIXER); not for general use.
<span class="h4"><a class="selflink" id="section-2.1.75" href="#section-2.1.75">2.1.75</a>. Header Field: X400-Trace</span>
Description:
X400 Trace
Applicable protocol: Mail [<a href="#ref-18" title=""Internet Message Format"">18</a>]
Status: standards-track
Author/change controller:
IETF (mailto:[email protected])
Internet Engineering Task Force
Specification document(s):
<a href="./rfc2156">RFC 2156</a> [<a href="#ref-10" title=""MIXER (Mime Internet X.400 Enhanced Relay): Mapping between X.400 and RFC 822/MIME"">10</a>]
Related information:
X400 Trace. <a href="./rfc2156">RFC 2156</a> (MIXER), not for general use.
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<span class="h3"><a class="selflink" id="section-2.2" href="#section-2.2">2.2</a>. Permanent MIME Header Field Registrations</span>
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
<span class="h4"><a class="selflink" id="section-2.2.1" href="#section-2.2.1">2.2.1</a>. Header Field: MIME-Version</span>
Description:
MIME version number
Applicable protocol: MIME [<a href="#ref-7" title=""Multipurpose Internet Mail Extensions (MIME) Part One: Format of Internet Message Bodies"">7</a>]
Status: standards-track
Author/change controller:
IETF (mailto:[email protected])
Internet Engineering Task Force
Specification document(s):
<a href="./rfc2045">RFC 2045</a> [<a href="#ref-7" title=""Multipurpose Internet Mail Extensions (MIME) Part One: Format of Internet Message Bodies"">7</a>] (<a href="#section-4">section 4</a>)
Related information:
An indicator that this message is formatted according to the MIME
standard, and an indication of which version of MIME is used.
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<span class="h4"><a class="selflink" id="section-2.2.2" href="#section-2.2.2">2.2.2</a>. Header Field: Content-ID</span>
Description:
Identify content body part
Applicable protocol: MIME [<a href="#ref-7" title=""Multipurpose Internet Mail Extensions (MIME) Part One: Format of Internet Message Bodies"">7</a>]
Status: standards-track
Author/change controller:
IETF (mailto:[email protected])
Internet Engineering Task Force
Specification document(s):
<a href="./rfc2045">RFC 2045</a> [<a href="#ref-7" title=""Multipurpose Internet Mail Extensions (MIME) Part One: Format of Internet Message Bodies"">7</a>] (<a href="#section-7">section 7</a>)
Related information:
Specifies a Unique ID for one MIME body part of the content of a
message.
<span class="h4"><a class="selflink" id="section-2.2.3" href="#section-2.2.3">2.2.3</a>. Header Field: Content-Description</span>
Description:
Description of message body part
Applicable protocol: MIME [<a href="#ref-7" title=""Multipurpose Internet Mail Extensions (MIME) Part One: Format of Internet Message Bodies"">7</a>]
Status: standards-track
Author/change controller:
IETF (mailto:[email protected])
Internet Engineering Task Force
Specification document(s):
<a href="./rfc2045">RFC 2045</a> [<a href="#ref-7" title=""Multipurpose Internet Mail Extensions (MIME) Part One: Format of Internet Message Bodies"">7</a>] (<a href="#section-8">section 8</a>)
Related information:
Description of a particular body part of a message; for example, a
caption for an image body part.
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<span class="h4"><a class="selflink" id="section-2.2.4" href="#section-2.2.4">2.2.4</a>. Header Field: Content-Transfer-Encoding</span>
Description:
Content transfer encoding applied
Applicable protocol: MIME [<a href="#ref-7" title=""Multipurpose Internet Mail Extensions (MIME) Part One: Format of Internet Message Bodies"">7</a>]
Status: standards-track
Author/change controller:
IETF (mailto:[email protected])
Internet Engineering Task Force
Specification document(s):
<a href="./rfc2045">RFC 2045</a> [<a href="#ref-7" title=""Multipurpose Internet Mail Extensions (MIME) Part One: Format of Internet Message Bodies"">7</a>] (<a href="#section-6">section 6</a>)
Related information:
Coding method used in a MIME message body part.
<span class="h4"><a class="selflink" id="section-2.2.5" href="#section-2.2.5">2.2.5</a>. Header Field: Content-Type</span>
Description:
MIME content type
Applicable protocol: MIME [<a href="#ref-7" title=""Multipurpose Internet Mail Extensions (MIME) Part One: Format of Internet Message Bodies"">7</a>]
Status: standards-track
Author/change controller:
IETF (mailto:[email protected])
Internet Engineering Task Force
Specification document(s):
<a href="./rfc2045">RFC 2045</a> [<a href="#ref-7" title=""Multipurpose Internet Mail Extensions (MIME) Part One: Format of Internet Message Bodies"">7</a>] (<a href="#section-5">section 5</a>)
Related information:
Format of content (character set, etc.) Note that the values for
this header field are defined in different ways in <a href="./rfc1049">RFC 1049</a> and in
MIME (<a href="./rfc2045">RFC 2045</a>). The 'MIME-version' header field will show
whether Content-Type is to be interpreted according to <a href="./rfc1049">RFC 1049</a> or
according to MIME. The MIME definition should be used in
generating mail. <a href="./rfc1049">RFC 1049</a> has 'historic' status. <a href="./rfc1766">RFC 1766</a> [<a href="#ref-5" title=""Tags for the Identification of Languages"">5</a>]
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 <a href="./rfc1049">RFC 1049</a>, <a href="./rfc1123">RFC 1123</a>: 5.2.13, and <a href="./rfc1766">RFC 1766</a>:
4.1.
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<span class="h4"><a class="selflink" id="section-2.2.6" href="#section-2.2.6">2.2.6</a>. Header Field: Content-Base</span>
Description:
Base to be used for resolving relative URIs within this content
part.
Applicable protocol: MIME [<a href="#ref-7" title=""Multipurpose Internet Mail Extensions (MIME) Part One: Format of Internet Message Bodies"">7</a>]
Status: standards-track
Author/change controller:
IETF (mailto:[email protected])
Internet Engineering Task Force
Specification document(s):
<a href="./rfc2110">RFC 2110</a> [<a href="#ref-8" title=""MIME E-mail Encapsulation of Aggregate Documents, such as HTML (MHTML)"">8</a>]
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 (<a href="./rfc2557">RFC 2557</a>).
<span class="h4"><a class="selflink" id="section-2.2.7" href="#section-2.2.7">2.2.7</a>. Header Field: Content-Location</span>
Description:
URI for retrieving a body part
Applicable protocol: MIME [<a href="#ref-7" title=""Multipurpose Internet Mail Extensions (MIME) Part One: Format of Internet Message Bodies"">7</a>]
Status: standards-track
Author/change controller:
IETF (mailto:[email protected])
Internet Engineering Task Force
Specification document(s):
<a href="./rfc2557">RFC 2557</a> [<a href="#ref-16" title=""MIME Encapsulation of Aggregate Documents, such as HTML (MHTML)"">16</a>]
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.
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<span class="h4"><a class="selflink" id="section-2.2.8" href="#section-2.2.8">2.2.8</a>. Header Field: Content-features</span>
Description:
Indicates content features of a MIME body part
Applicable protocol: MIME [<a href="#ref-7" title=""Multipurpose Internet Mail Extensions (MIME) Part One: Format of Internet Message Bodies"">7</a>]
Status: standards-track
Author/change controller:
IETF (mailto:[email protected])
Internet Engineering Task Force
Specification document(s):
<a href="./rfc2912">RFC 2912</a> [<a href="#ref-19" title=""Indicating Media Features for MIME Content"">19</a>] (<a href="#section-3">section 3</a>)
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 <a href="./rfc2533">RFC 2533</a>, <a href="./rfc2506">RFC 2506</a>, and <a href="./rfc2045">RFC 2045</a>.
<span class="h4"><a class="selflink" id="section-2.2.9" href="#section-2.2.9">2.2.9</a>. Header Field: Content-Disposition</span>
Description:
Intended content disposition and file name
Applicable protocol: MIME [<a href="#ref-7" title=""Multipurpose Internet Mail Extensions (MIME) Part One: Format of Internet Message Bodies"">7</a>]
Status: standards-track
Author/change controller:
IETF (mailto:[email protected])
Internet Engineering Task Force
Specification document(s):
<a href="./rfc2183">RFC 2183</a> [<a href="#ref-11" title=""Communicating Presentation Information in Internet Messages: The Content- Disposition Header Field"">11</a>]
Related information:
Indicates 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.
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<span class="h4"><a class="selflink" id="section-2.2.10" href="#section-2.2.10">2.2.10</a>. Header Field: Content-Language</span>
Description:
Language of message content
Applicable protocol: MIME [<a href="#ref-7" title=""Multipurpose Internet Mail Extensions (MIME) Part One: Format of Internet Message Bodies"">7</a>]
Status: standards-track
Author/change controller:
IETF (mailto:[email protected])
Internet Engineering Task Force
Specification document(s):
<a href="./rfc3282">RFC 3282</a> [<a href="#ref-21" title=""Content Language Headers"">21</a>]
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.
<span class="h4"><a class="selflink" id="section-2.2.11" href="#section-2.2.11">2.2.11</a>. Header Field: Content-Alternative</span>
Description:
Alternative content available
Applicable protocol: MIME [<a href="#ref-7" title=""Multipurpose Internet Mail Extensions (MIME) Part One: Format of Internet Message Bodies"">7</a>]
Status: work-in-progress
Author/change controller:
IETF (mailto:[email protected])
Internet Engineering Task Force
Specification document(s):
<a href="./rfc3297">RFC 3297</a> [<a href="#ref-22" title=""Content Negotiation for Messaging Services based on Email"">22</a>]
Related information:
Information about the media features of alternative content
formats available for the current message.
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<span class="h4"><a class="selflink" id="section-2.2.12" href="#section-2.2.12">2.2.12</a>. Header Field: Content-MD5</span>
Description:
MD5 checksum of content
Applicable protocol: MIME [<a href="#ref-7" title=""Multipurpose Internet Mail Extensions (MIME) Part One: Format of Internet Message Bodies"">7</a>]
Status: standards-track
Author/change controller:
IETF (mailto:[email protected])
Internet Engineering Task Force
Specification document(s):
<a href="./rfc1864">RFC 1864</a> [<a href="#ref-6" title=""The Content-MD5 Header Field"">6</a>]
Related information:
Checksum of content to ensure that it has not been modified.
<span class="h4"><a class="selflink" id="section-2.2.13" href="#section-2.2.13">2.2.13</a>. Header Field: Content-Duration</span>
Description:
Time duration of content
Applicable protocol: MIME [<a href="#ref-7" title=""Multipurpose Internet Mail Extensions (MIME) Part One: Format of Internet Message Bodies"">7</a>]
Status: standards-track
Author/change controller:
IETF (mailto:[email protected])
Internet Engineering Task Force
Specification document(s):
<a href="./rfc2424">RFC 2424</a> [<a href="#ref-15" title=""Content Duration MIME Header Definition"">15</a>]
Related information:
Time duration of body part content, in seconds (e.g., for audio
message).
<span class="h2"><a class="selflink" id="section-3" href="#section-3">3</a>. IANA Considerations</span>
<a href="#section-2">Section 2</a> of this specification provides initial registrations of
mail and MIME header fields in the "Permanent Message Header Field
Registry", defined by registration procedures for message header
fields [<a href="#ref-1" title=""Registration Procedures for Message Header Fields"">1</a>].
<span class="grey">G. Klyne, et al. Standards Track [Page 50]</span><span id="page-51" ></span>
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<span class="h2"><a class="selflink" id="section-4" href="#section-4">4</a>. Security Considerations</span>
No security considerations are introduced by this registration
document beyond those already inherent in use of the mail message
header fields referenced.
<span class="h2"><a class="selflink" id="section-5" href="#section-5">5</a>. Acknowledgements</span>
Most of the information in this document has been derived from Jacob
Palme's work in <a href="./rfc2076">RFC 2076</a> [<a href="#ref-25" title=""Common Internet Message Headers"">25</a>] and subsequent updates [<a href="#ref-26" title=""Common Internet Message Header Fields"">26</a>]. The
authors also gratefully acknowledge contributions and constructive
input from Mark Nottingham, Bruce Lilly, Keith Moore, and Charles
Lindsey (the mention of whom is not intended to imply their
unqualified support for material herein).
<span class="h2"><a class="selflink" id="section-6" href="#section-6">6</a>. References</span>
<span class="h3"><a class="selflink" id="section-6.1" href="#section-6.1">6.1</a>. Normative References</span>
[<a id="ref-1">1</a>] Klyne, G., Nottingham, M., and J. Mogul, "Registration
Procedures for Message Header Fields", <a href="https://www.rfc-editor.org/bcp/bcp90">BCP 90</a>, <a href="./rfc3864">RFC 3864</a>,
September 2004.
[<a id="ref-2">2</a>] Crocker, D., "Standard for the format of ARPA Internet text
messages", STD 11, <a href="./rfc822">RFC 822</a>, August 1982.
[<a id="ref-3">3</a>] Hardcastle-Kille, S., "Mapping between X.400(1988) / ISO 10021
and <a href="./rfc822">RFC 822</a>", <a href="./rfc1327">RFC 1327</a>, May 1992.
[<a id="ref-4">4</a>] Costanzo, A., Robinson, D., and R. Ullmann, "Encoding Header
Field for Internet Messages", <a href="./rfc1505">RFC 1505</a>, August 1993.
[<a id="ref-5">5</a>] Alvestrand, H., "Tags for the Identification of Languages", <a href="./rfc1766">RFC</a>
<a href="./rfc1766">1766</a>, March 1995.
[<a id="ref-6">6</a>] Myers, J. and M. Rose, "The Content-MD5 Header Field", <a href="./rfc1864">RFC 1864</a>,
October 1995.
[<a id="ref-7">7</a>] Freed, N. and N. Borenstein, "Multipurpose Internet Mail
Extensions (MIME) Part One: Format of Internet Message Bodies",
<a href="./rfc2045">RFC 2045</a>, November 1996.
[<a id="ref-8">8</a>] Palme, J. and A. Hopmann, "MIME E-mail Encapsulation of
Aggregate Documents, such as HTML (MHTML)", <a href="./rfc2110">RFC 2110</a>, March
1997.
[<a id="ref-9">9</a>] Bradner, S., "Key words for use in RFCs to Indicate Requirement
Levels", <a href="https://www.rfc-editor.org/bcp/bcp14">BCP 14</a>, <a href="./rfc2119">RFC 2119</a>, March 1997.
<span class="grey">G. Klyne, et al. Standards Track [Page 51]</span><span id="page-52" ></span>
<span class="grey"><a href="./rfc4021">RFC 4021</a> Mail and MIME Header Fields March 2005</span>
[<a id="ref-10">10</a>] Kille, S., "MIXER (Mime Internet X.400 Enhanced Relay): Mapping
between X.400 and <a href="./rfc822">RFC 822</a>/MIME", <a href="./rfc2156">RFC 2156</a>, January 1998.
[<a id="ref-11">11</a>] Troost, R., Dorner, S., and K. Moore, "Communicating
Presentation Information in Internet Messages: The Content-
Disposition Header Field", <a href="./rfc2183">RFC 2183</a>, August 1997.
[<a id="ref-12">12</a>] Hansen, T. and G. Vaudreuil, "Message Disposition Notification",
<a href="./rfc3798">RFC 3798</a>, May 2004.
[<a id="ref-13">13</a>] Neufeld, G. and J. Baer, "The Use of URLs as Meta-Syntax for
Core Mail List Commands and their Transport through Message
Header Fields", <a href="./rfc2369">RFC 2369</a>, July 1998.
[<a id="ref-14">14</a>] Vaudreuil, G. and G. Parsons, "Voice Profile for Internet Mail -
version 2 (VPIMv2)", <a href="./rfc3801">RFC 3801</a>, June 2004.
[<a id="ref-15">15</a>] Vaudreuil, G. and G. Parsons, "Content Duration MIME Header
Definition", <a href="./rfc3803">RFC 3803</a>, June 2004.
[<a id="ref-16">16</a>] Palme, J., Hopmann, A., and N. Shelness, "MIME Encapsulation of
Aggregate Documents, such as HTML (MHTML)", <a href="./rfc2557">RFC 2557</a>, March
1999.
[<a id="ref-17">17</a>] Klensin, J., "Simple Mail Transfer Protocol", <a href="./rfc2821">RFC 2821</a>, April
2001.
[<a id="ref-18">18</a>] Resnick, P., "Internet Message Format", <a href="./rfc2822">RFC 2822</a>, April 2001.
[<a id="ref-19">19</a>] Klyne, G., "Indicating Media Features for MIME Content", <a href="./rfc2912">RFC</a>
<a href="./rfc2912">2912</a>, September 2000.
[<a id="ref-20">20</a>] Chandhok, R. and G. Wenger, "List-Id: A Structured Field and
Namespace for the Identification of Mailing Lists", <a href="./rfc2919">RFC 2919</a>,
March 2001.
[<a id="ref-21">21</a>] Alvestrand, H., "Content Language Headers", <a href="./rfc3282">RFC 3282</a>, May 2002.
[<a id="ref-22">22</a>] Klyne, G., Iwazaki, R., and D. Crocker, "Content Negotiation for
Messaging Services based on Email", <a href="./rfc3297">RFC 3297</a>, July 2002.
[<a id="ref-23">23</a>] Burger, E., Candell, E., Eliot, C., and G. Klyne, "Message
Context for Internet Mail", <a href="./rfc3458">RFC 3458</a>, January 2003.
[<a id="ref-24">24</a>] Miller, J., Krauskopf, T., Resnick, P. and W. Treese, "PICS
Label Distribution Label Syntax and Communication Protocols",
W3C Recommendation REC-PICS-labels, October 1996,
<<a href="http://www.w3.org/TR/REC-PICS-labels">http://www.w3.org/TR/REC-PICS-labels</a>>.
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<span class="h3"><a class="selflink" id="section-6.2" href="#section-6.2">6.2</a>. Informative References</span>
[<a id="ref-25">25</a>] Palme, J., "Common Internet Message Headers", <a href="./rfc2076">RFC 2076</a>, February
1997.
[<a id="ref-26">26</a>] Palme, J., <a style="text-decoration: none" href='https://www.google.com/search?sitesearch=datatracker.ietf.org%2Fdoc%2Fhtml%2F&q=inurl:draft-+%22Common+Internet+Message+Header+Fields%22'>"Common Internet Message Header Fields"</a>, Work in
Progress.
URIs
[<a id="ref-27">27</a>] <<a href="http://www.ninebynine.org/IETF/Messaging/HdrRegistry/Intro.html">http://www.ninebynine.org/IETF/Messaging/HdrRegistry/</a>
<a href="http://www.ninebynine.org/IETF/Messaging/HdrRegistry/Intro.html">Intro.html</a>>
Authors' Addresses
Graham Klyne
Image Bioinformatics Research Group
Department of Zoology, University of Oxford
South Parks Road, Oxford OX1 3PS, UK
Phone: +44-(0)1865-281991
Fax: +44-(0)1865-310447
EMail: [email protected]
Jacob Palme
Stockholm University/KTH
Forum 100
Kista S-164 40
Sweden
Phone: +46-8-16 16 67
Fax: +46-8-783 08 29
EMail: [email protected]
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Full Copyright Statement
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Acknowledgement
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Internet Society.
<span class="h2"><a class="selflink" id="appendix-G" href="#appendix-G">G</a>. Klyne, et al. Standards Track [Page 54]</span>
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