draft-ietf-usefor-usefor-12.txt   rfc5536.txt 
Usenet Format Working Group K. Murchison, Ed. Network Working Group K. Murchison, Ed.
Internet-Draft Carnegie Mellon University Request for Comments: 5536 Carnegie Mellon University
Obsoletes: 1036 (if approved) C. Lindsey Obsoletes: 1036 C. Lindsey
Intended status: Standards Track University of Manchester Category: Standards Track University of Manchester
Expires: July 12, 2007 D. Kohn D. Kohn
FlyDash, Inc. Healing Thresholds
January 8, 2007 November 2009
Netnews Article Format Netnews Article Format
draft-ietf-usefor-usefor-12
Status of this Memo Abstract
By submitting this Internet-Draft, each author represents that any This document specifies the syntax of Netnews articles in the context
applicable patent or other IPR claims of which he or she is aware of the Internet Message Format (RFC 5322) and Multipurpose Internet
have been or will be disclosed, and any of which he or she becomes Mail Extensions (MIME) (RFC 2045). This document obsoletes RFC 1036,
aware will be disclosed, in accordance with Section 6 of BCP 79. providing an updated specification to reflect current practice and
incorporating incremental changes specified in other documents.
Internet-Drafts are working documents of the Internet Engineering Status of This Memo
Task Force (IETF), its areas, and its working groups. Note that
other groups may also distribute working documents as Internet-
Drafts.
Internet-Drafts are draft documents valid for a maximum of six months This document specifies an Internet standards track protocol for the
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time. It is inappropriate to use Internet-Drafts as reference improvements. Please refer to the current edition of the "Internet
material or to cite them other than as "work in progress." Official Protocol Standards" (STD 1) for the standardization state
and status of this protocol. Distribution of this memo is unlimited.
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Copyright (C) The IETF Trust (2007). RFC 5536 Netnews Article Format November 2009
Abstract the copyright in such materials, this document may not be modified
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it for publication as an RFC or to translate it into languages other
than English.
This document specifies the syntax of Netnews articles in the context RFC 5536 Netnews Article Format November 2009
of the "Internet Message Format" (RFC 2822) and "Multipurpose
Internet Mail Extensions (MIME)" (RFC 2045). This document obsoletes
RFC 1036, providing an updated specification to reflect current
practice and incorporating incremental changes specified in other
documents.
Table of Contents Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 4 1. Introduction ....................................................4
1.1. Basic Concepts . . . . . . . . . . . . . . . . . . . . . . 4 1.1. Basic Concepts .............................................4
1.2. Scope . . . . . . . . . . . . . . . . . . . . . . . . . . 4 1.2. Scope ......................................................4
1.3. Requirements Notation . . . . . . . . . . . . . . . . . . 4 1.3. Requirements Notation ......................................4
1.4. Syntax Notation . . . . . . . . . . . . . . . . . . . . . 5 1.4. Syntax Notation ............................................5
1.5. Definitions . . . . . . . . . . . . . . . . . . . . . . . 5 1.5. Definitions ................................................5
1.6. Structure of This Document . . . . . . . . . . . . . . . . 7 1.6. Structure of This Document .................................7
2. Format . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 2. Format ..........................................................7
2.1. Base . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 2.1. Base .......................................................7
2.2. Header Fields . . . . . . . . . . . . . . . . . . . . . . 8 2.2. Header Fields ..............................................8
2.3. MIME Conformance . . . . . . . . . . . . . . . . . . . . . 10 2.3. MIME Conformance ...........................................9
3. News Header Fields . . . . . . . . . . . . . . . . . . . . . . 11 3. News Header Fields ..............................................9
3.1. Mandatory Header Fields . . . . . . . . . . . . . . . . . 11 3.1. Mandatory Header Fields ...................................10
3.1.1. Date . . . . . . . . . . . . . . . . . . . . . . . . . 12 3.1.1. Date ...............................................11
3.1.2. From . . . . . . . . . . . . . . . . . . . . . . . . . 12 3.1.2. From ...............................................11
3.1.3. Message-ID . . . . . . . . . . . . . . . . . . . . . . 12 3.1.3. Message-ID .........................................11
3.1.4. Newsgroups . . . . . . . . . . . . . . . . . . . . . . 15 3.1.4. Newsgroups .........................................13
3.1.5. Path . . . . . . . . . . . . . . . . . . . . . . . . . 16 3.1.5. Path ...............................................14
3.1.6. Subject . . . . . . . . . . . . . . . . . . . . . . . 18 3.1.6. Subject ............................................16
3.2. Optional Header Fields . . . . . . . . . . . . . . . . . . 18 3.2. Optional Header Fields ....................................16
3.2.1. Approved . . . . . . . . . . . . . . . . . . . . . . . 19 3.2.1. Approved ...........................................17
3.2.2. Archive . . . . . . . . . . . . . . . . . . . . . . . 19 3.2.2. Archive ............................................17
3.2.3. Control . . . . . . . . . . . . . . . . . . . . . . . 20 3.2.3. Control ............................................17
3.2.4. Distribution . . . . . . . . . . . . . . . . . . . . . 20 3.2.4. Distribution .......................................18
3.2.5. Expires . . . . . . . . . . . . . . . . . . . . . . . 21 3.2.5. Expires ............................................19
3.2.6. Followup-To . . . . . . . . . . . . . . . . . . . . . 21 3.2.6. Followup-To ........................................19
3.2.7. Injection-Date . . . . . . . . . . . . . . . . . . . . 22 3.2.7. Injection-Date .....................................20
3.2.8. Injection-Info . . . . . . . . . . . . . . . . . . . . 22 3.2.8. Injection-Info .....................................20
3.2.9. Organization . . . . . . . . . . . . . . . . . . . . . 24 3.2.9. Organization .......................................22
3.2.10. References . . . . . . . . . . . . . . . . . . . . . . 24 3.2.10. References ........................................22
3.2.11. Summary . . . . . . . . . . . . . . . . . . . . . . . 25 3.2.11. Summary ...........................................23
3.2.12. Supersedes . . . . . . . . . . . . . . . . . . . . . . 25 3.2.12. Supersedes ........................................23
3.2.13. User-Agent . . . . . . . . . . . . . . . . . . . . . . 25 3.2.13. User-Agent ........................................23
3.2.14. Xref . . . . . . . . . . . . . . . . . . . . . . . . . 26 3.2.14. Xref ..............................................24
3.3. Obsolete Header Fields . . . . . . . . . . . . . . . . . . 26 3.3. Obsolete Header Fields ....................................25
3.3.1. Lines . . . . . . . . . . . . . . . . . . . . . . . . 27 3.3.1. Lines ..............................................25
4. Internationalization Considerations ............................25
5. Security Considerations ........................................25
6. IANA Considerations ............................................26
7. References .....................................................31
7.1. Normative References ......................................31
7.2. Informative References ....................................32
Appendix A. Acknowledgments ......................................34
Appendix B. Differences from RFC 1036 and Its Derivatives ........34
Appendix C. Differences from RFC 5322 ............................35
4. Internationalization Considerations . . . . . . . . . . . . . 28 RFC 5536 Netnews Article Format November 2009
5. Security Considerations . . . . . . . . . . . . . . . . . . . 29
6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 30
7. References . . . . . . . . . . . . . . . . . . . . . . . . . . 35
7.1. Normative References . . . . . . . . . . . . . . . . . . . 35
7.2. Informative References . . . . . . . . . . . . . . . . . . 36
Appendix A. Acknowledgments . . . . . . . . . . . . . . . . . . . 38
Appendix B. Differences from RFC 1036 and its derivatives . . . . 39
Appendix C. Differences from RFC 2822 . . . . . . . . . . . . . . 40
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 41
Intellectual Property and Copyright Statements . . . . . . . . . . 42
1. Introduction 1. Introduction
1.1. Basic Concepts 1.1. Basic Concepts
"Netnews" is a set of protocols for generating, storing and "Netnews" is a set of protocols for generating, storing, and
retrieving news "articles" (whose format is a subset of that for retrieving news "articles" (whose format is a subset of that for
Email messages), and for exchanging them amongst a readership that is Email messages), and for exchanging them amongst a readership that is
potentially widely distributed. It is organized around "newsgroups", potentially widely distributed. It is organized around "newsgroups",
with the expectation that each reader will be able to see all with the expectation that each reader will be able to see all
articles posted to each newsgroup in which he participates. These articles posted to each newsgroup in which he participates. These
protocols most commonly use a flooding algorithm which propagates protocols most commonly use a flooding algorithm, which propagates
copies throughout a network of participating servers. Typically, copies throughout a network of participating servers. Typically,
only one copy is stored per server, and each server makes it only one copy is stored per server, and each server makes it
available on demand to readers able to access that server. available on demand to readers who are able to access that server.
1.2. Scope 1.2. Scope
This document specifies the syntax of Netnews articles in the context This document specifies the syntax of Netnews articles in the context
of the "Internet Message Format" [RFC2822] and "Multipurpose Internet of the Internet Message Format [RFC5322] and Multipurpose Internet
Mail Extensions (MIME)" [RFC2045]. This document obsoletes Mail Extensions (MIME) [RFC2045]. This document obsoletes [RFC1036],
[RFC1036], updating the syntax of Netnews articles to reflect current updating the syntax of Netnews articles to reflect current practice
practice and incorporating changes and clarifications specified in and incorporating changes and clarifications specified in other
other documents such as [Son-of-1036]. documents such as [Son-of-1036].
This is the first in a set of documents that obsolete [RFC1036]. This is the first in a set of documents that obsolete [RFC1036].
This document focuses on the syntax and semantics of Netnews This document focuses on the syntax and semantics of Netnews
articles. [I-D.ietf-usefor-usepro] is also a standards-track articles. [RFC5537] is also a Standards Track document and describes
document and describes the protocol issues of Netnews articles, the protocol issues of Netnews articles, independent of transport
independent of transport protocols such as NNTP [RFC3977]. A best- protocols such as the Network News Transfer Protocol (NNTP)
common-practice document, [I-D.ietf-usefor-useage], describes [RFC3977]. [USEAGE], "Usenet Best Practice", describes
implementation recommendations to improve interoperability and implementation recommendations to improve interoperability and
usability. usability.
This specification is intended as a definition of what article This specification is intended as a definition of what article
content format is to be passed between systems. Although many news content format is to be passed between systems. Although many news
systems locally store articles in this format (which eliminates the systems locally store articles in this format (which eliminates the
need for translation between formats), local storage is outside of need for translation between formats), local storage is outside of
the scope of this standard. the scope of this standard.
1.3. Requirements Notation 1.3. Requirements Notation
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
document are to be interpreted as described in [RFC2119]. document are to be interpreted as described in [RFC2119].
RFC 5536 Netnews Article Format November 2009
1.4. Syntax Notation 1.4. Syntax Notation
Header fields defined in this specification use the Augmented Backus- Header fields defined in this specification use the Augmented Backus-
Naur Form (ABNF) notation (including the Core Rules) specified in Naur Form (ABNF) notation (including the Core Rules) specified in
[RFC4234] and many constructs defined in [RFC2822], [RFC2045] as [RFC5234] as well as many constructs defined in [RFC5322], [RFC2045]
updated by [RFC2231], and [RFC3986], specifically: as updated by [RFC2231], and [RFC3986]. Specifically:
token = <see RFC2045 Section 5.1> token = <see RFC 2045 Section 5.1>
value = <see RFC2045 Section 5.1> value = <see RFC 2045 Section 5.1>
parameter = <see RFC2231 Section 7> parameter = <see RFC 2231 Section 7>
attribute = <see RFC2231 Section 7> attribute = <see RFC 2231 Section 7>
FWS = <see RFC2822 Section 3.2.3> FWS = <see RFC 5322 Section 3.2.2>
comment = <see RFC2822 Section 3.2.3> comment = <see RFC 5322 Section 3.2.2>
CFWS = <see RFC2822 Section 3.2.3> CFWS = <see RFC 5322 Section 3.2.2>
atext = <see RFC2822 Section 3.2.4> atext = <see RFC 5322 Section 3.2.3>
dot-atom-text = <see RFC2822 Section 3.2.4> dot-atom-text = <see RFC 5322 Section 3.2.3>
phrase = <see RFC2822 Section 3.2.6> phrase = <see RFC 5322 Section 3.2.5>
utext = <see RFC2822 Section 3.2.6> date-time = <see RFC 5322 Section 3.3>
date-time = <see RFC2822 Section 3.3> mailbox = <see RFC 5322 Section 3.4>
mailbox = <see RFC2822 Section 3.4> mailbox-list = <see RFC 5322 Section 3.4>
mailbox-list = <see RFC2822 Section 3.4> address-list = <see RFC 5322 Section 3.4>
address-list = <see RFC2822 Section 3.4> body = <see RFC 5322 Section 3.5>
body = <see RFC2822 Section 3.5> fields = <see RFC 5322 Section 3.6>
fields = <see RFC2822 Section 3.6>
IPv6address = <see RFC3986 Section 3.2.2> IPv6address = <see RFC 3986 Section 3.2.2>
IPv4address = <see RFC3986 Section 3.2.2> IPv4address = <see RFC 3986 Section 3.2.2>
ALPHA = <see RFC4234 Appendix B.1> ALPHA = <see RFC 5234 Appendix B.1>
CRLF = <see RFC4234 Appendix B.1> CRLF = <see RFC 5234 Appendix B.1>
DIGIT = <see RFC4234 Appendix B.1> DIGIT = <see RFC 5234 Appendix B.1>
DQUOTE = <see RFC4234 Appendix B.1> DQUOTE = <see RFC 5234 Appendix B.1>
SP = <see RFC4234 Appendix B.1> SP = <see RFC 5234 Appendix B.1>
VCHAR = <see RFC 5234 Appendix B.1>
Additionally, Section 3.1.3 specifies a stricter definition of Additionally, Section 3.1.3 specifies a stricter definition of
<msg-id> than the syntax in [RFC2822] Section 3.6.4. <msg-id> than the syntax in Section 3.6.4 of [RFC5322].
1.5. Definitions 1.5. Definitions
An "article" is the unit of Netnews, analogous to an [RFC2822] An "article" is the unit of Netnews, analogous to an [RFC5322]
"message". A "proto-article" is one that has not yet been injected "message". A "proto-article" is one that has not yet been injected
into the news system. In contrast to an "article", a "proto-article" into the news system. In contrast to an article, a proto-article may
may lack some mandatory header fields. lack some mandatory header fields.
A "message identifier" (Section 3.1.3) is a unique identifier for an A "message identifier" (Section 3.1.3) is a unique identifier for an
article, usually supplied by the "user agent" that posted it or, article, usually supplied by the user agent that posted it or,
failing that, by the "news server". It distinguishes the article failing that, by the "news server". It distinguishes the article
RFC 5536 Netnews Article Format November 2009
from every other article ever posted anywhere. Articles with the from every other article ever posted anywhere. Articles with the
same message identifier are treated as if they are the same article same message identifier are treated as if they are the same article
regardless of any differences in the body or header fields. regardless of any differences in the body or header fields.
A "newsgroup" is a forum having a name and intended for articles on a A "newsgroup" is a forum having a name and that is intended for
specific topic. An article is "posted to" a single newsgroup or articles on a specific topic. An article is "posted to" a single
several newsgroups. When an article is posted to more than one newsgroup or several newsgroups. When an article is posted to more
newsgroup, it is said to be "crossposted"; note that this differs than one newsgroup, it is said to be "crossposted"; note that this
from posting the same text as part of each of several articles, one differs from posting the same text as part of each of several
per newsgroup. articles, one per newsgroup.
A newsgroup may be "moderated", in which case submissions are not A newsgroup may be "moderated", in which case submissions are not
posted directly, but mailed to a "moderator" for consideration and posted directly, but mailed to a "moderator" for consideration and
possible posting. Moderators are typically human but may be possible posting. Moderators are typically human but may be
implemented partially or entirely in software. implemented partially or entirely in software.
A "poster" is the person or software that composes and submits a A "poster" is the person or software that composes and submits a
potentially compliant article to a "user agent". potentially compliant article to a user agent.
A "reader" is the person or software reading Netnews articles. A "reader" is the person or software reading Netnews articles.
A "followup" is an article containing a response to the contents of A "followup" is an article containing a response to the contents of
an earlier article, its "precursor". Every followup includes a an earlier article, its "precursor". Every followup includes a
"References" header field identifying that precursor (but note that "References" header field identifying that precursor (but note that
non-followup articles may also use a References header field). non-followup articles may also use a References header field).
A "control message" is an article which is marked as containing A "control message" is an article that is marked as containing
control information; a news server receiving such an article may control information; a news server receiving such an article may
(subject to the policies observed at that site) take actions beyond (subject to the policies observed at that site) take actions beyond
just filing and passing on the article. just filing and passing on the article.
A "news server" is software that may accept articles from a "user A news server is software that may accept articles from a user agent,
agent", and/or make articles available to user agents, and/or and/or make articles available to user agents, and/or exchange
exchange articles with other news servers. articles with other news servers.
A "user agent" is software that may help posters submit proto- A "user agent" is software that may help posters submit proto-
articles to a news server, and/or fetch articles from a news server articles to a news server, and/or fetch articles from a news server
and present them to a reader, and/or assist the reader in creating and present them to a reader, and/or assist the reader in creating
articles and followups. articles and followups.
The generic term "agent" is used when describing requirements that The generic term "agent" is used when describing requirements that
apply to both user agents and news servers. apply to both user agents and news servers.
An agent is said to "generate" a construct if it did not exist before An agent is said to "generate" a construct if it did not exist before
the agent created it. Examples are when a user agent creates a the agent created it. Examples are when a user agent creates a
message from text and addressing information supplied by a user, or message from text and addressing information supplied by a user, or
when a news server creates an "Injection-Info" header field for a when a news server creates an "Injection-Info" header field for a
newly posted message. newly posted message.
RFC 5536 Netnews Article Format November 2009
An agent is said to "accept" a construct if some other entity An agent is said to "accept" a construct if some other entity
generates it and passes it to the agent in question, and the agent generates it and passes it to the agent in question, and the agent
processes it without treating it as a format or protocol error. processes it without treating it as a format or protocol error.
1.6. Structure of This Document 1.6. Structure of This Document
This document uses a cite-by-reference methodology, rather than This document uses a cite-by-reference methodology, rather than
repeating the contents of other standards, which could otherwise repeating the contents of other standards, which could otherwise
result in subtle differences and interoperability challenges. result in subtle differences and interoperability challenges.
Although this document is as a result rather short, it requires Although this document is as a result rather short, it requires
skipping to change at page 8, line 10 skipping to change at page 7, line 29
Section 2 defines the format of Netnews articles. Section 3 details Section 2 defines the format of Netnews articles. Section 3 details
the header fields necessary to make an article suitable for the the header fields necessary to make an article suitable for the
Netnews environment. Netnews environment.
2. Format 2. Format
2.1. Base 2.1. Base
An article is said to be conformant to this specification if it An article is said to be conformant to this specification if it
conforms to the format specified in [RFC2822] Section 3 and to the conforms to the format specified in Section 3 of [RFC5322] and to the
additional requirements of this specification. additional requirements of this specification.
An article that uses the obsolete syntax specified in Section 4 of An article that uses the obsolete syntax specified in Section 4 of
[RFC2822] is NOT conformant to this specification, except for the [RFC5322] is NOT conformant to this specification, except for the
following two cases: following two cases:
o Articles are conformant if they use the <obs-phrase> construct o Articles are conformant if they use the <obs-phrase> construct
(use of a phrase like "John Q. Public" without the use of quotes, (use of a phrase like "John Q. Public" without the use of quotes,
see [RFC2822] Section 4.1) but agents MUST NOT generate see Section 4.1 of [RFC5322]), but agents MUST NOT generate
productions of such syntax. productions of such syntax.
o Articles are conformant if they use the "GMT" <zone>, as specified o Articles are conformant if they use the "GMT" <zone>, as specified
in Section 3.1.1. in Section 3.1.1.
This document, and specifications that build upon it, specify how to This document, and specifications that build upon it, specify how to
handle conformant articles. Handling of non-conformant articles is handle conformant articles. Handling of non-conformant articles is
outside the scope of this specification. outside the scope of this specification.
Agents conforming to this specification MUST generate only conformant Agents conforming to this specification MUST generate only conformant
articles. articles.
The text below uses ABNF to specify restrictions on the syntax The text below uses ABNF to specify restrictions on the syntax
specified in [RFC2822]; this grammar is intended to be more specified in [RFC5322]; this grammar is intended to be more
restrictive than the [RFC2822] grammar. Articles must conform to the restrictive than the [RFC5322] grammar. Articles must conform to the
ABNF specified in [RFC2822] and also to the restrictions specified
RFC 5536 Netnews Article Format November 2009
ABNF specified in [RFC5322] and also to the restrictions specified
here, both those that are expressed as text and those that are here, both those that are expressed as text and those that are
expressed as ABNF. expressed as ABNF.
NOTE: Other specifications use the term "header" as a synonym for NOTE: Other specifications use the term "header" as a synonym for
what [RFC2822] calls "header field". This document follows the what [RFC5322] calls "header field". This document follows the
terminology in Section 2 of [RFC2822] in using the terms "line", terminology in Section 2 of [RFC5322] in using the terms "line",
"header field", "header field name", "header field body", and "header field", "header field name", "header field body", and
"folding", based on a belief that consistent terminology among "folding", based on a belief that consistent terminology among
specifications that depend on each other makes the specifications specifications that depend on each other makes the specifications
easier to use in the long run. easier to use in the long run.
2.2. Header Fields 2.2. Header Fields
All header fields in a Netnews article are compliant with [RFC2822]; All header fields in a Netnews article are compliant with [RFC5322];
this specification, however, is less permissive in what can be this specification, however, is less permissive in what can be
generated and accepted by agents. The syntax allowed for Netnews generated and accepted by agents. The syntax allowed for Netnews
article headers is a strict subset of the "Internet Message Format" article headers is a strict subset of the Internet Message Format
headers, making all headers compliant with this specification headers, making all headers compliant with this specification
inherently compliant with [RFC2822]. Note however that the converse inherently compliant with [RFC5322]. Note however that the converse
is not guaranteed to be true in all cases. is not guaranteed to be true in all cases.
General rules which apply to all header fields (even those documented General rules that apply to all header fields (even those documented
in [RFC2822] and [RFC2045]) are listed below, and those that apply to in [RFC5322] and [RFC2045]) are listed below, and those that apply to
specific header fields are described in the relevant sections of this specific header fields are described in the relevant sections of this
document. document.
o All agents MUST generate header fields so that at least one space o All agents MUST generate header fields so that at least one space
immediately follows the ':' separating the header field name and immediately follows the ':' separating the header field name and
the header field body (for compatibility with deployed software, the header field body (for compatibility with deployed software,
including NNTP [RFC3977] servers). News agents MAY accept header including NNTP [RFC3977] servers). News agents MAY accept header
fields which do not contain the required space. fields that do not contain the required space.
o Every line of a header field body (including the first and any o Every line of a header field body (including the first and any
that are subsequently folded) MUST contain at least one non- that are subsequently folded) MUST contain at least one non-
whitespace character. whitespace character.
NOTE: This means that no header field body defined by or NOTE: This means that no header field body defined by or
referenced by this document can be empty. As a result, rather referenced by this document can be empty. As a result, rather
than using the <unstructured> syntax from Section 3.2.6 of than using the <unstructured> syntax from Section 3.2.5 of
[RFC2822], this document uses a stricter definition: [RFC5322], this document uses a stricter definition:
unstructured = *WSP utext *( [FWS] utext ) *WSP unstructured = *WSP VCHAR *( [FWS] VCHAR ) *WSP
NOTE: The [RFC2822] specification sometimes uses [FWS] at the NOTE: The [RFC5322] specification sometimes uses [FWS] at the
beginning or end of ABNF describing header field content. This beginning or end of ABNF describing header field content. This
specification uses *WSP in such cases, also in cases where this specification uses *WSP in such cases, also in cases where this
specification redefines constructs from [RFC2822]. This is specification redefines constructs from [RFC5322]. This is
RFC 5536 Netnews Article Format November 2009
done for consistency with the restriction described here, but done for consistency with the restriction described here, but
the restriction applies to all header fields, not just those the restriction applies to all header fields, not just those
where ABNF is defined in this document. where ABNF is defined in this document.
o Compliant software MUST NOT generate (but MAY accept) header field o Compliant software MUST NOT generate (but MAY accept) header field
lines of more than 998 octets. This is the only limit on the lines of more than 998 octets. This is the only limit on the
length of a header field line prescribed by this standard. length of a header field line prescribed by this standard.
However, specific rules to the contrary may apply in particular However, specific rules to the contrary may apply in particular
cases (for example, according to [RFC2047], lines of a header cases (for example, according to [RFC2047], lines of a header
field containing encoded-words are limited to 76 octets). field containing encoded words are limited to 76 octets).
[I-D.ietf-usefor-useage] includes suggested limits for convenience [USEAGE] includes suggested limits for convenience of display by
of display by user agents. user agents.
NOTE: As stated in [RFC2822], there is NO restriction on the NOTE: As stated in [RFC5322], there is NO restriction on the
number of lines into which a header field may be split, and number of lines into which a header field may be split, and
hence there is NO restriction on the total length of a header hence there is NO restriction on the total length of a header
field (in particular it may, by suitable folding, be made to field (in particular it may, by suitable folding, be made to
exceed the 998 octets restriction pertaining to a single header exceed the 998-octet restriction pertaining to a single header
field line). field line).
o The character set for header fields is US-ASCII. Where the use of o The character set for header fields is US-ASCII. Where the use of
non-ASCII characters is required, they MUST be encoded using the non-ASCII characters is required, they MUST be encoded using the
MIME mechanisms defined in [RFC2047] and [RFC2231]. MIME mechanisms defined in [RFC2047] and [RFC2231].
2.3. MIME Conformance 2.3. MIME Conformance
User agents MUST meet the definition of MIME conformance in [RFC2049] User agents MUST meet the definition of MIME conformance in [RFC2049]
and MUST also support [RFC2231]. This level of MIME conformance and MUST also support [RFC2231]. This level of MIME conformance
provides support for internationalization and multimedia in message provides support for internationalization and multimedia in message
bodies ([RFC2045], [RFC2046], [RFC2231]), and support for bodies [RFC2045], [RFC2046], and [RFC2231], and support for
internationalization of header fields ([RFC2047], [RFC2231]). Note internationalization of header fields [RFC2047] and [RFC2231]. Note
that [Errata] currently exist for [RFC2046] and [RFC2231]. that [Errata] currently exist for [RFC2045], [RFC2046], [RFC2047] and
[RFC2231].
For the purposes of Section 5 of [RFC2047], all header fields defined For the purposes of Section 5 of [RFC2047], all header fields defined
in Section 3 of this standard are to be considered as "extension in Section 3 of this standard are to be considered as "extension
message header fields", permitting the use of [RFC2047] encodings message header fields", permitting the use of [RFC2047] encodings
within any <unstructured> header field, or within any <comment> or within any <unstructured> header field, or within any <comment> or
<phrase> permitted within any structured header field. <phrase> permitted within any structured header field.
User agents MAY accept and generate other MIME extension header User agents MAY accept and generate other MIME extension header
fields, and in particular SHOULD accept Content-Disposition [RFC2183] fields, and in particular SHOULD accept Content-Disposition [RFC2183]
and Content-Language [RFC3282]. and Content-Language [RFC3282].
3. News Header Fields 3. News Header Fields
The following news header fields extend those defined in Section 3.6 The following news header fields extend those defined in Section 3.6
of [RFC2822]: of [RFC5322]:
RFC 5536 Netnews Article Format November 2009
fields =/ *( approved / fields =/ *( approved /
archive / archive /
control / control /
distribution / distribution /
expires / expires /
followup-to / followup-to /
injection-date / injection-date /
injection-info / injection-info /
lines / lines /
newsgroups / newsgroups /
organization / organization /
path / path /
summary / summary /
supersedes / supersedes /
user-agent / user-agent /
xref ) xref )
Each of these header fields may occur at most once in a news article. Each of these header fields MUST NOT occur more than once in a news
article.
The following header fields defined in this document do not allow The following header fields defined in this document do not allow
comments (CFWS): <comment>s (i.e., they use FWS rather than CFWS).
Control Control
Distribution Distribution
Followup-To Followup-To
Newsgroups
Lines Lines
Newsgroups
Path Path
Supersedes Supersedes
Xref Xref
This also applies to the following header field defined in [RFC2822]: This also applies to the following header field defined in [RFC5322]:
Message-ID Message-ID
Most of these header fields are mainly of interest to news servers, Most of these header fields are mainly of interest to news servers,
and news servers often need to process these fields very rapidly. and news servers often need to process these fields very rapidly.
Thus some header fields prohibit <comment>s. Thus, some header fields prohibit <comment>s.
3.1. Mandatory Header Fields 3.1. Mandatory Header Fields
Each Netnews article conformant with this specification MUST have Each Netnews article conformant with this specification MUST have
exactly one of each of the following header fields: Date, From, exactly one of each of the following header fields: Date, From,
Message-ID, Newsgroups, Path, Subject. Message-ID, Newsgroups, Path, and Subject.
RFC 5536 Netnews Article Format November 2009
3.1.1. Date 3.1.1. Date
The Date header field is the same as that specified in Sections 3.3 The Date header field is the same as that specified in Sections 3.3
and 3.6.1 of [RFC2822] with the added restrictions detailed above in and 3.6.1 of [RFC5322], with the added restrictions detailed above in
Section 2.2. However, the use of "GMT" as a time zone (part of <obs- Section 2.2. However, the use of "GMT" as a time zone (part of
zone>), although deprecated, is widespread in Netnews articles today. <obs-zone>), although deprecated, is widespread in Netnews articles
Therefore, agents MUST accept <date-time> constructs that use the today. Therefore, agents MUST accept <date-time> constructs that use
"GMT" zone. the "GMT" zone.
orig-date = "Date:" SP date-time CRLF orig-date = "Date:" SP date-time CRLF
NOTE: This specification does not change [RFC2822], which says NOTE: This specification does not change [RFC5322], which says
that agents MUST NOT generate <date-time> constructs which include that agents MUST NOT generate <date-time> constructs that include
any zone names defined by <obs-zone>. any zone names defined by <obs-zone>.
Software that accepts dates with unknown timezones SHOULD treat such Software that accepts dates with unknown timezones SHOULD treat such
timezones as equivalent to "-0000" when comparing dates, as specified timezones as equivalent to "-0000" when comparing dates, as specified
in [RFC2822] Section 4.3. in Section 4.3 of [RFC5322].
Also note that these requirements apply wherever <date-time> is used, Also note that these requirements apply wherever <date-time> is used,
including Injection-Date and Expires in Section 3.2.7 and including Injection-Date and Expires (Sections 3.2.7 and 3.2.5,
Section 3.2.5, respectively. respectively).
3.1.2. From 3.1.2. From
The From header field is the same as that specified in Section 3.6.2 The From header field is the same as that specified in Section 3.6.2
of [RFC2822] with the added restrictions detailed above in of [RFC5322], with the added restrictions detailed above in
Section 2.2. Section 2.2.
from = "From:" SP mailbox-list CRLF from = "From:" SP mailbox-list CRLF
3.1.3. Message-ID 3.1.3. Message-ID
The Message-ID header field contains a unique message identifier. The Message-ID header field contains a unique message identifier.
Netnews is more dependent on message identifier uniqueness and fast Netnews is more dependent on message identifier uniqueness and fast
comparison than Email is, and some news software and standards comparison than Email is, and some news software and standards
[RFC3977] might have trouble with the full range of possible [RFC3977] might have trouble with the full range of possible
<msg-id>s permitted by [RFC2822]. This section therefore restricts <msg-id>s permitted by [RFC5322]. This section therefore restricts
the syntax of <msg-id> as compared to Section 3.6.4 of [RFC2822]. the syntax of <msg-id> as compared to Section 3.6.4 of [RFC5322].
The global uniqueness requirement for <msg-id> in [RFC2822] is to be The global uniqueness requirement for <msg-id> in [RFC5322] is to be
understood as applying across all protocols using such message understood as applying across all protocols using such message
identifiers, and across both Email and Netnews in particular. identifiers, and across both Email and Netnews in particular.
message-id = "Message-ID:" SP *WSP msg-id *WSP CRLF message-id = "Message-ID:" SP *WSP msg-id *WSP CRLF
msg-id = "<" msg-id-core ">" msg-id = "<" msg-id-core ">"
; maximum length is 250 octets ; maximum length is 250 octets
RFC 5536 Netnews Article Format November 2009
msg-id-core = id-left "@" id-right msg-id-core = id-left "@" id-right
id-left = dot-atom-text / no-fold-quote id-left = dot-atom-text
id-right = dot-atom-text / no-fold-literal id-right = dot-atom-text / no-fold-literal
no-fold-quote = DQUOTE no-fold-literal = "[" *mdtext "]"
( "." *mqtext /
*mqtext "." /
*mqtext mqspecial *mqtext )
DQUOTE
mqtext = atext / "." / mqspecial
mqspecial = "(" / ")" / ; same as specials except
"<" / ; "\" and DQUOTE quoted
"[" / "]" / ; "." doubled and ">" omitted
":" / ";" /
"@" / "," /
".." / "\\" / "\" DQUOTE
no-fold-literal = "[" *( mdtext / "\[" / "\]" / "\\" ) "]"
mdtext = %d33-61 / ; The rest of the US-ASCII mdtext = %d33-61 / ; The rest of the US-ASCII
%d63-90 / ; characters not including %d63-90 / ; characters not including
%d94-126 ; ">", "[", "]", or "\" %d94-126 ; ">", "[", "]", or "\"
The msg-id MUST NOT be more than 250 octets in length. The <msg-id> MUST NOT be more than 250 octets in length.
NOTE: The length restriction ensures that systems that accept NOTE: The length restriction ensures that systems that accept
message identifiers as a parameter when referencing an article message identifiers as a parameter when referencing an article
(e.g. [RFC3977]) can rely on a bounded length. (e.g., [RFC3977]) can rely on a bounded length.
Observe that msg-id includes the < and >. Observe that <msg-id> includes the < and >.
Observe also that in contrast to the corresponding header field in Observe also that in contrast to the corresponding header field in
[RFC2822]: [RFC5322]:
o the syntax does not allow comments within the Message-ID header
field,
o it ensures that no string of characters is quoted if it were
already a <dot-atom-text> (it MUST start or end with a ".", or
contain at least one <mqspecial>),
o it ensures that no single character is prefixed by a "\" in the
form of a <quoted-pair> unless strictly necessary,
o it excludes all control characters, o The syntax does not allow comments within the Message-ID header
field.
o there is no possibility for ">" or WSP to occur inside a <msg-id>, o There is no possibility for ">" or WSP to occur inside a <msg-id>.
whether quoted or not, and
o even though commonly derived from <domain>s, <id-rights>s are o Even though commonly derived from <domain>s, <id-rights>s are
case-sensitive (and thus, once created, are not to be altered case-sensitive (and thus, once created, are not to be altered
during subsequent transmission or copying) during subsequent transmission or copying)
This is to simplify processing by news servers and to ensure This is to simplify processing by news servers and to ensure
interoperability with existing implementations and compliance with interoperability with existing implementations and compliance with
[RFC3977]. Thus, whereas under [RFC2822] the following <msg-id>s [RFC3977]. A simple comparison of octets will always suffice to
would be considered semantically equivalent,
<ab.cd@example.com>
<"ab.cd"@example.com>
<"ab.\cd"@example.com>
only the first of them is syntactically permitted by this standard,
and hence a simple comparison of octets will always suffice to
determine the identity of two <msg-id>s. determine the identity of two <msg-id>s.
Also note that this updated ABNF applies wherever <msg-id> is used, Also note that this updated ABNF applies wherever <msg-id> is used,
including the References header field discussed in Section 3.2.10 and including the References header field discussed in Section 3.2.10 and
the Supersedes header field discussed in Section 3.2.12. the Supersedes header field discussed in Section 3.2.12.
Some software will try to match the <id-right> of a <msg-id> in a Some software will try to match the <id-right> of a <msg-id> in a
case-insensitive fashion; some will match it in a case-sensitive case-insensitive fashion; some will match it in a case-sensitive
fashion. Implementations MUST NOT generate a Message-ID where the fashion. Implementations MUST NOT generate a Message-ID where the
only difference from another Message-ID is the case of characters in only difference from another Message-ID is the case of characters in
the <id-right> part. the <id-right> part.
RFC 5536 Netnews Article Format November 2009
When generating a <msg-id>, implementations SHOULD use a domain name When generating a <msg-id>, implementations SHOULD use a domain name
as the <id-right>. as the <id-right>.
NOTE: Section 3.6.4 of [RFC2822] recommends that the <id-right> NOTE: Section 3.6.4 of [RFC5322] recommends that the <id-right>
should be a domain name or a domain literal. Domain literals are should be a domain name or a domain literal. Domain literals are
troublesome since many IP addresses are not globally unique; troublesome since many IP addresses are not globally unique;
domain names are more likely to generate unique Message-IDs. domain names are more likely to generate unique Message-IDs.
3.1.4. Newsgroups 3.1.4. Newsgroups
The Newsgroups header field specifies the newsgroup(s) to which the The Newsgroups header field specifies the newsgroup(s) to which the
article is posted. article is posted.
newsgroups = "Newsgroups:" SP newsgroup-list CRLF newsgroups = "Newsgroups:" SP newsgroup-list CRLF
skipping to change at page 15, line 39 skipping to change at page 13, line 49
but MUST NOT be used otherwise. but MUST NOT be used otherwise.
NOTE: All-digit <component>s conflict with one widely used storage NOTE: All-digit <component>s conflict with one widely used storage
scheme for articles. Mixed-case groups cause confusion between scheme for articles. Mixed-case groups cause confusion between
systems with case-sensitive matching and systems with case- systems with case-sensitive matching and systems with case-
insensitive matching of <newsgroup-name>s. insensitive matching of <newsgroup-name>s.
<component>s beginning with underline ("_") are reserved for use by <component>s beginning with underline ("_") are reserved for use by
future versions of this standard and SHOULD NOT be generated by user future versions of this standard and SHOULD NOT be generated by user
agents (whether in header fields or in newgroup control messages as agents (whether in header fields or in newgroup control messages as
defined by [I-D.ietf-usefor-usepro]). However, such names MUST be defined by [RFC5537]). However, such names MUST be accepted by news
accepted by news servers. servers.
RFC 5536 Netnews Article Format November 2009
<component>s beginning with "+" and "-" are reserved for private use <component>s beginning with "+" and "-" are reserved for private use
and SHOULD NOT be generated by user agents (whether in header fields and SHOULD NOT be generated by user agents (whether in header fields
or in newgroup control messages [I-D.ietf-usefor-usepro]) without a or in newgroup control messages [RFC5537]) without a private prior
private prior agreement to do so. However, such names MUST be agreement to do so. However, such names MUST be accepted by news
accepted by news servers. servers.
The following <newsgroup-name>s are reserved and MUST NOT be used as The following <newsgroup-name>s are reserved and MUST NOT be used as
the name of a newsgroup: the name of a newsgroup:
o Groups whose first (or only) <component> is "example" o Groups whose first (or only) <component> is "example"
o The group "poster" o The group "poster"
The following <newsgroup-name>s have been used for specific purposes The following <newsgroup-name>s have been used for specific purposes
in various implementations and protocols and therefore MUST NOT be in various implementations and protocols and therefore MUST NOT be
used for the names of normal newsgroups. They MAY be used for their used for the names of normal newsgroups. They MAY be used for their
specific purpose or by local agreement. specific purpose or by local agreement.
o Groups whose first (or only) component is "to" o Groups whose first (or only) component is "to"
o Groups whose first (or only) component is "control" o Groups whose first (or only) component is "control"
skipping to change at page 16, line 15 skipping to change at page 14, line 29
The following <newsgroup-name>s have been used for specific purposes The following <newsgroup-name>s have been used for specific purposes
in various implementations and protocols and therefore MUST NOT be in various implementations and protocols and therefore MUST NOT be
used for the names of normal newsgroups. They MAY be used for their used for the names of normal newsgroups. They MAY be used for their
specific purpose or by local agreement. specific purpose or by local agreement.
o Groups whose first (or only) component is "to" o Groups whose first (or only) component is "to"
o Groups whose first (or only) component is "control" o Groups whose first (or only) component is "control"
o Groups which contain (or consist only of) the component "all" o Groups that contain (or consist only of) the component "all"
o Groups which contain (or consist only of) the component "ctl" o Groups that contain (or consist only of) the component "ctl"
o The group "junk" o The group "junk"
NOTE: "example.*" is reserved for examples in this and other NOTE: "example.*" is reserved for examples in this and other
standards; "poster" has a special meaning in the Followup-To standards; "poster" has a special meaning in the Followup-To
header field; "to.*" is reserved for certain point-to-point header field; "to.*" is reserved for certain point-to-point
communications in conjunction with the "ihave" control message as communications in conjunction with the "ihave" control message as
defined in [I-D.ietf-usefor-usepro]; "control.*" and "junk" have defined in [RFC5537]; "control.*" and "junk" have special meanings
special meanings in some news servers; "all" is used as a wildcard in some news servers; "all" is used as a wildcard in some
in some implementations; and "ctl" was formerly used to indicate a implementations; and "ctl" was formerly used to indicate a
<control-command> within the Newsgroups header field. <control-command> within the Newsgroups header field.
3.1.5. Path 3.1.5. Path
The Path header field indicates the route taken by an article since The Path header field indicates the route taken by an article since
its injection into the Netnews system. Each agent that processes an its injection into the Netnews system. Each agent that processes an
article is required to prepend at least one <path-identity> to this article is required to prepend at least one <path-identity> to this
header field body. This is primarily so that news servers are able header field body. This is primarily so that news servers are able
to avoid sending articles to sites already known to have them, in to avoid sending articles to sites already known to have them, in
particular the site they came from, and additionally to permit particular the site they came from. Additionally, it permits
tracing the route articles take in moving over the network, and for gathering statistics and tracing the route articles take in moving
gathering statistics. over the network.
RFC 5536 Netnews Article Format November 2009
path = "Path:" SP *WSP path-list tail-entry *WSP CRLF path = "Path:" SP *WSP path-list tail-entry *WSP CRLF
path-list = *( path-identity [FWS] [path-diagnostic] "!" ) path-list = *( path-identity [FWS] [path-diagnostic] "!" )
path-diagnostic = diag-match / diag-other / diag-deprecated path-diagnostic = diag-match / diag-other / diag-deprecated
diag-match = "!" ; another "!" diag-match = "!" ; another "!"
diag-other = "!." diag-keyword [ "." diag-identity ] [FWS] diag-other = "!." diag-keyword [ "." diag-identity ] [FWS]
diag-deprecated = "!" IPv4address [FWS] diag-deprecated = "!" IPv4address [FWS]
diag-keyword = 1*ALPHA ; see [I-D.ietf-usefor-usepro] diag-keyword = 1*ALPHA ; see [RFC5537]
diag-identity = path-identity / IPv4address / IPv6address diag-identity = path-identity / IPv4address / IPv6address
tail-entry = path-nodot tail-entry = path-nodot
; may be the string "not-for-mail" ; may be the string "not-for-mail"
path-identity = ( 1*( label "." ) toplabel ) / path-nodot path-identity = ( 1*( label "." ) toplabel ) / path-nodot
path-nodot = 1*( alphanum / "-" / "_" ) ; legacy names path-nodot = 1*( alphanum / "-" / "_" ) ; legacy names
label = alphanum [ *( alphanum / "-" ) alphanum ] label = alphanum [ *( alphanum / "-" ) alphanum ]
toplabel = ( [ label *( "-" ) ] ALPHA *( "-" ) label ) / toplabel = ( [ label *( "-" ) ] ALPHA *( "-" ) label ) /
( label *( "-" ) ALPHA [ *( "-" ) label ] ) / ( label *( "-" ) ALPHA [ *( "-" ) label ] ) /
( label 1*( "-" ) label ) ( label 1*( "-" ) label )
alphanum = ALPHA / DIGIT ; compare RFC3696 alphanum = ALPHA / DIGIT ; compare [RFC3696]
A <path-identity> is a name identifying a site. It takes the form of A <path-identity> is a name identifying a site. It takes the form of
a domain name having two or more components separated by dots, or a a domain name having two or more components separated by dots, or a
single name with no dots (<path-nodot>). single name with no dots (<path-nodot>).
Each <path-identity> in the <path-list> (which does not include the Each <path-identity> in the <path-list> (which does not include the
<tail-entry>) indicates, from right to left, the successive agents <tail-entry>) indicates, from right to left, the successive agents
through which the article has passed. The use of the <diag-match>, through which the article has passed. The use of the <diag-match>,
which appears as "!!", indicates that the agent to its left verified which appears as "!!", indicates that the agent to its left verified
the identity of the agent to its right before accepting the article the identity of the agent to its right before accepting the article
(whereas the <path-delimiter> "!" implies no such claim). (whereas the <path-delimiter> "!" implies no such claim).
NOTE: Historically, the <tail-entry> indicated the name of the NOTE: Historically, the <tail-entry> indicated the name of the
sender. If not used for this purpose, the string "not-for-mail" sender. If not used for this purpose, the string "not-for-mail"
is often used instead (since at one time the whole path could be is often used instead (since at one time the whole path could be
used as a mail address for the sender). used as a mail address for the sender).
NOTE: Although case-insensitive, it is intended that the <diag- RFC 5536 Netnews Article Format November 2009
keyword>s should be in uppercase, to distinguish them from the
<path-identity>s which are traditionally in lowercase. NOTE: Although case-insensitive, it is intended that the
<diag-keyword>s should be in uppercase, to distinguish them from
the <path-identity>s, which are traditionally in lowercase.
A <path-diagnostic> is an item inserted into the Path header field A <path-diagnostic> is an item inserted into the Path header field
for purposes other than to indicate the name of a site. The use of for purposes other than to indicate the name of a site. The use of
these is described in [I-D.ietf-usefor-usepro]. these is described in [RFC5537].
NOTE: One usage of a <path-diagnostic> is to record an IP address. NOTE: One usage of a <path-diagnostic> is to record an IP address.
The fact that <IPv6address>es are allowed means that the colon (:) The fact that <IPv6address>es are allowed means that the colon (:)
is permitted; note that this may cause interoperability problems is permitted; note that this may cause interoperability problems
at older sites that regard ":" as a <path-delimiter> and have at older sites that regard ":" as a <path-delimiter> and have
neighbors whose names have 4 or fewer characters, and where all neighbors whose names have 4 or fewer characters, and where all
the characters are valid HEX digits. the characters are valid HEX digits.
NOTE: Although <IPv4address>es have occasionally been used in the NOTE: Although <IPv4address>es have occasionally been used in the
past (usually with a diagnostic intent), their continued use is past (usually with a diagnostic intent), their continued use is
deprecated (though it is still acceptable in the form of the deprecated (though it is still acceptable in the form of the
<diag-deprecated>). <diag-deprecated>).
3.1.6. Subject 3.1.6. Subject
The Subject header field is the same as that specified in Section The Subject header field is the same as that specified in Section
3.6.5 of [RFC2822] with the added restrictions detailed above in 3.6.5 of [RFC5322], with the added restrictions detailed above in
Section 2.2. Further discussion of the content of the Subject header Section 2.2. Further discussion of the content of the Subject header
field appears in [I-D.ietf-usefor-usepro] and field appears in [RFC5537] and [USEAGE].
[I-D.ietf-usefor-useage].
subject = "Subject:" SP unstructured CRLF subject = "Subject:" SP unstructured CRLF
3.2. Optional Header Fields 3.2. Optional Header Fields
None of the header fields appearing in this section is required to None of the header fields appearing in this section are required to
appear in every article, but some of them may be required in certain appear in every article, but some of them may be required in certain
types of article. Further discussion of these requirements appears types of articles. Further discussion of these requirements appears
in [I-D.ietf-usefor-usepro] and [I-D.ietf-usefor-useage]. in [RFC5537] and [USEAGE].
The header fields Comments, Keywords, Reply-To, and Sender are used The header fields Comments, Keywords, Reply-To, and Sender are used
in Netnews articles in the same circumstances and with the same in Netnews articles in the same circumstances and with the same
meanings as those specified in [RFC2822] with the added restrictions meanings as those specified in [RFC5322], with the added restrictions
detailed above in Section 2.2. Multiple occurrences of the Keywords detailed above in Section 2.2. Multiple occurrences of the Keywords
header field are not permitted. header field are not permitted.
comments = "Comments:" SP unstructured CRLF comments = "Comments:" SP unstructured CRLF
keywords = "Keywords:" SP phrase *("," phrase) CRLF keywords = "Keywords:" SP phrase *("," phrase) CRLF
RFC 5536 Netnews Article Format November 2009
reply-to = "Reply-To:" SP address-list CRLF reply-to = "Reply-To:" SP address-list CRLF
sender = "Sender:" SP mailbox CRLF sender = "Sender:" SP mailbox CRLF
The MIME header fields MIME-Version, Content-Type, Content-Transfer- The MIME header fields MIME-Version, Content-Type, Content-Transfer-
Encoding, Content-Disposition, and Content-Language are used in Encoding, Content-Disposition, and Content-Language are used in
Netnews articles in the same circumstances and with the same meanings Netnews articles in the same circumstances and with the same meanings
as those specified in [RFC2045], [RFC2183], and [RFC3282] with the as those specified in [RFC2045], [RFC2183], and [RFC3282], with the
added restrictions detailed above in Section 2.2. added restrictions detailed above in Section 2.2.
All remaining news header fields are described below. All remaining news header fields are described below.
3.2.1. Approved 3.2.1. Approved
The Approved header field indicates the mailing addresses (and The Approved header field indicates the mailing addresses (and
possibly the full names) of the persons or entities approving the possibly the full names) of the persons or entities approving the
article for posting. Its principal uses are in moderated articles article for posting. Its principal uses are in moderated articles
and in group control messages; see [I-D.ietf-usefor-usepro]. and in group control messages; see [RFC5537].
approved = "Approved:" SP mailbox-list CRLF approved = "Approved:" SP mailbox-list CRLF
3.2.2. Archive 3.2.2. Archive
The Archive header field provides an indication of the poster's The Archive header field provides an indication of the poster's
intent regarding preservation of the article in publicly accessible intent regarding preservation of the article in publicly accessible
long-term or permanent storage. long-term or permanent storage.
archive = "Archive:" SP [CFWS] ("no" / "yes") archive = "Archive:" SP [CFWS] ("no" / "yes")
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archive-param = parameter archive-param = parameter
The presence of an Archive header field in an article with a field The presence of an Archive header field in an article with a field
body of "no" indicates that the poster does not permit redistribution body of "no" indicates that the poster does not permit redistribution
from publicly accessible long-term or permanent archives. A field from publicly accessible long-term or permanent archives. A field
body of "yes" indicates that the poster permits such redistribution. body of "yes" indicates that the poster permits such redistribution.
No <parameter>s are currently defined; if present, they can be No <parameter>s are currently defined; if present, they can be
ignored. Further discussion of the use of the Archive header field ignored. Further discussion of the use of the Archive header field
appears in [I-D.ietf-usefor-useage]. appears in [USEAGE].
3.2.3. Control 3.2.3. Control
The Control header field marks the article as a control message and The Control header field marks the article as a control message and
specifies the desired actions (additional to the usual ones of specifies the desired actions (in addition to the usual actions of
storing and/or relaying the article). storing and/or relaying the article).
RFC 5536 Netnews Article Format November 2009
control = "Control:" SP *WSP control-command *WSP CRLF control = "Control:" SP *WSP control-command *WSP CRLF
control-command = verb *( 1*WSP argument ) control-command = verb *( 1*WSP argument )
verb = token verb = token
argument = 1*( %x21-7E ) argument = 1*( %x21-7E )
The verb indicates what action should be taken, and the argument(s) The verb indicates what action should be taken, and the argument(s)
(if any) supply details. In some cases, the <body> (as defined in (if any) supply details. In some cases, the <body> (as defined in
[RFC2822]) of the article may also contain details. The legal verbs [RFC5322]) of the article may also contain details. The legal verbs
and respective arguments are discussed in the companion document, and respective arguments are discussed in the companion document,
[I-D.ietf-usefor-usepro]. [RFC5537].
An article with a Control header field MUST NOT also have a An article with a Control header field MUST NOT also have a
Supersedes header field. Supersedes header field.
3.2.4. Distribution 3.2.4. Distribution
The Distribution header field specifies geographic or organizational The Distribution header field specifies geographic or organizational
limits on an article's propagation. limits on an article's propagation.
distribution = "Distribution:" SP dist-list CRLF distribution = "Distribution:" SP dist-list CRLF
skipping to change at page 20, line 49 skipping to change at page 18, line 45
*( ALPHA / DIGIT / "+" / "-" / "_" ) *( ALPHA / DIGIT / "+" / "-" / "_" )
The <dist-name>s "world" and "local" are reserved. "world" indicates The <dist-name>s "world" and "local" are reserved. "world" indicates
unlimited distribution and SHOULD NOT be used explicitly, since it is unlimited distribution and SHOULD NOT be used explicitly, since it is
the default when the Distribution header field is absent entirely. the default when the Distribution header field is absent entirely.
"local" is reserved for indicating distribution only to the local "local" is reserved for indicating distribution only to the local
site, as defined by local software configuration. site, as defined by local software configuration.
"All" MUST NOT be used as a <dist-name>. <dist-name>s SHOULD contain "All" MUST NOT be used as a <dist-name>. <dist-name>s SHOULD contain
at least three characters, except when they are two-letter country at least three characters, except when they are two-letter country
codes drawn from [ISO3166-1]. <dist-name>s are case-insensitive (i.e. codes drawn from [ISO3166-1]. <dist-name>s are case-insensitive
"US", "Us", "uS", and "us" all specify the same distribution). (i.e., "US", "Us", "uS", and "us" all specify the same distribution).
Optional FWS in the <dist-list> SHOULD NOT be generated, but MUST be Optional FWS in the <dist-list> SHOULD NOT be generated, but MUST be
accepted. accepted.
RFC 5536 Netnews Article Format November 2009
3.2.5. Expires 3.2.5. Expires
The Expires header field specifies a date and time when the poster The Expires header field specifies a date and time when the poster
deems the article to be no longer relevant and could usefully be deems the article to be no longer relevant and could usefully be
removed ("expired"). removed ("expired").
NOTE: This header field is useful when the poster desires an NOTE: This header field is useful when the poster desires an
unusually long or an unusually short expiry time. unusually long or an unusually short expiry time.
expires = "Expires:" SP date-time CRLF expires = "Expires:" SP date-time CRLF
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that followups should be emailed directly to the article's poster that followups should be emailed directly to the article's poster
(using the addresses contained in the Reply-To header field if one (using the addresses contained in the Reply-To header field if one
exists, otherwise using the addresses contained in the From header exists, otherwise using the addresses contained in the From header
field) rather than posted to any newsgroups. Agents MUST generate field) rather than posted to any newsgroups. Agents MUST generate
the keyword "poster" in lowercase, but MAY choose to recognize case- the keyword "poster" in lowercase, but MAY choose to recognize case-
insensitive forms such as "Poster". insensitive forms such as "Poster".
As in the Newsgroups (Section 3.1.4) header field, optional FWS in As in the Newsgroups (Section 3.1.4) header field, optional FWS in
the <newsgroup-list> SHOULD NOT be generated, but MUST be accepted. the <newsgroup-list> SHOULD NOT be generated, but MUST be accepted.
RFC 5536 Netnews Article Format November 2009
3.2.7. Injection-Date 3.2.7. Injection-Date
The Injection-Date header field contains the date and time that the The Injection-Date header field contains the date and time that the
article was injected into the network. Its purpose is to enable news article was injected into the network. Its purpose is to enable news
servers, when checking for "stale" articles, to use a <date-time> servers, when checking for "stale" articles, to use a <date-time>
that was added by a news server at injection time rather than one that was added by a news server at injection time rather than one
added by the user agent at message composition time. added by the user agent at message composition time.
This header field MUST be inserted whenever an article is injected. This header field MUST be inserted whenever an article is injected.
However, software that predates this standard does not use this However, software that predates this standard does not use this
skipping to change at page 22, line 30 skipping to change at page 20, line 32
See the remarks under Section 3.1.1 regarding the syntax of See the remarks under Section 3.1.1 regarding the syntax of
<date-time> and the requirements and recommendations to which it is <date-time> and the requirements and recommendations to which it is
subject. subject.
NOTE: Since clocks on various agents are not necessarily NOTE: Since clocks on various agents are not necessarily
synchronized, the <date-time> in this header field might not be a synchronized, the <date-time> in this header field might not be a
later value than that in the Date header field. Agents MUST NOT later value than that in the Date header field. Agents MUST NOT
alter a pre-existing Date header field when adding an Injection- alter a pre-existing Date header field when adding an Injection-
Date header field. Date header field.
This header field is intended to replace the currently-used but This header field is intended to replace the currently used but
undocumented "NNTP-Posting-Date" header field, whose use is now undocumented "NNTP-Posting-Date" header field, whose use is now
deprecated. deprecated.
3.2.8. Injection-Info 3.2.8. Injection-Info
The Injection-Info header field contains information provided by the The Injection-Info header field contains information provided by the
injecting news server as to how an article entered the Netnews system injecting news server as to how an article entered the Netnews
and to assist in tracing its true origin. It can also specify one or system; it assists in tracing the article's true origin. It can also
more addresses where complaints concerning the poster of the article specify one or more addresses where complaints concerning the poster
may be sent. of the article may be sent.
injection-info = "Injection-Info:" SP [CFWS] path-identity injection-info = "Injection-Info:" SP [CFWS] path-identity
[CFWS] *( ";" [CFWS] parameter ) [CFWS] CRLF [CFWS] *( ";" [CFWS] parameter ) [CFWS] CRLF
NOTE: The syntax of <parameter> ([RFC2045] Section 5.1 as amended NOTE: The syntax of <parameter> (Section 5.1 of [RFC2045], as
by [RFC2231]), taken in conjunction with the folding rules of amended by [RFC2231]), taken in conjunction with the folding rules
[RFC0822] (sic), effectively allows [CFWS] to occur on either side of [RFC0822] (note: not [RFC2822] or [RFC5322]), effectively
of the "=" inside a <parameter>. allows [CFWS] to occur on either side of the "=" inside a
<parameter>.
RFC 5536 Netnews Article Format November 2009
The following table gives the <attribute> and the format of the The following table gives the <attribute> and the format of the
<value> for each <parameter> defined for use with this header field. <value> for each <parameter> defined for use with this header field.
At most, one occurrence of each such <parameter> is allowed.
At most one occurrence of each such <parameter> is allowed.
<attribute> format of <value> <attribute> format of <value>
-------------------- ----------------- -------------------- -----------------
"posting-host" a <host-value> "posting-host" a <host-value>
"posting-account" any <value> "posting-account" any <value>
"logging-data" any <value> "logging-data" any <value>
"mail-complaints-to" an <address-list> "mail-complaints-to" an <address-list>
where where
skipping to change at page 23, line 29 skipping to change at page 21, line 33
NOTE: Since any such <host-value> or <address-list> also has to be NOTE: Since any such <host-value> or <address-list> also has to be
a syntactically correct <value>, it will usually be necessary to a syntactically correct <value>, it will usually be necessary to
encapsulate it as a <quoted-string>, for example: encapsulate it as a <quoted-string>, for example:
posting-host = "posting.example.com:192.0.2.1" posting-host = "posting.example.com:192.0.2.1"
Other <attribute>s SHOULD NOT be used unless defined in extensions to Other <attribute>s SHOULD NOT be used unless defined in extensions to
this standard. If non-standards-based <attribute>s are used, they this standard. If non-standards-based <attribute>s are used, they
MUST begin with an "x-". MUST begin with an "x-".
Although comments and folding of white space are permitted throughout Although comments and folding of whitespace are permitted throughout
the Injection-Info header field, folding SHOULD NOT be used within the Injection-Info header field, folding SHOULD NOT be used within
any <parameter>. Folding SHOULD only occur before or after the ";" any <parameter>. Folding SHOULD only occur before or after the ";"
separating <parameter>s, and comments SHOULD only be used following separating <parameter>s, and comments SHOULD only be used following
the last <parameter>. the last <parameter>.
NOTE: Some of this information has previously been sent in non- NOTE: Some of this information has previously been sent in non-
standardized header fields such as NNTP-Posting-Host, X-Trace, standardized header fields such as NNTP-Posting-Host, X-Trace,
X-Complaints-To, and others. Once a news server generates an X-Complaints-To, and others. Once a news server generates an
Injection-Info header field, it should have no need to send these Injection-Info header field, it should have no need to send these
non-standard header fields. non-standard header fields.
The "posting-host" <parameter> specifies the FQDN and/or IP address The "posting-host" <parameter> specifies the Fully Qualified Domain
(IPv4address or IPv6address) of the host from which the news server Name (FQDN) and/or IP address (IPv4address or IPv6address) of the
received the article. host from which the news server received the article.
NOTE: If the "posting-host" <parameter> fails to deterministically NOTE: If the "posting-host" <parameter> fails to deterministically
identify the host (e.g. dynamic IP address allocation), the identify the host (e.g., dynamic IP address allocation), the
"posting-account" or the "logging-data" <parameter> may provide "posting-account" or "logging-data" <parameter> may provide
additional information about the true origin of the article. additional information about the true origin of the article.
RFC 5536 Netnews Article Format November 2009
The "posting-account" <parameter> identifies the source from which The "posting-account" <parameter> identifies the source from which
that news server received the article, in a notation that can be that news server received the article, in a notation that can be
interpreted by the news server administrator. This notation can interpreted by the news server administrator. This notation can
include any information the administrator deems pertinent. In order include any information the administrator deems pertinent. In order
to limit the exposure of personal data, it SHOULD be given in a form to limit the exposure of personal data, it SHOULD be given in a form
that cannot be interpreted by other sites. However, to make it that cannot be interpreted by other sites. However, to make it
useful for rate limiting and abuse detection, two messages posted useful for rate limiting and abuse detection, two messages posted
from the same source SHOULD have the same value of "posting-account", from the same source SHOULD have the same value of "posting-account",
and two messages from different sources SHOULD have differing values and two messages from different sources SHOULD have differing values
of "posting-account". The exact definition of "source" is left to of "posting-account". The exact definition of "source" is left to
skipping to change at page 24, line 25 skipping to change at page 22, line 31
account) that will enable the true origin of the article to be account) that will enable the true origin of the article to be
determined by reference to logging information kept by the news determined by reference to logging information kept by the news
server. server.
The "mail-complaints-to" <parameter> specifies one or more mailboxes The "mail-complaints-to" <parameter> specifies one or more mailboxes
for sending complaints concerning the behavior of the poster of the for sending complaints concerning the behavior of the poster of the
article. article.
It is a matter of local policy which of the above <parameter>s to It is a matter of local policy which of the above <parameter>s to
include. Some pieces of information have privacy implications; this include. Some pieces of information have privacy implications; this
is discussed in [I-D.ietf-usefor-useage]. is discussed in [USEAGE].
3.2.9. Organization 3.2.9. Organization
The Organization header field is a short phrase identifying the The Organization header field is a short phrase identifying the
poster's organization. poster's organization.
organization = "Organization:" SP unstructured CRLF organization = "Organization:" SP unstructured CRLF
NOTE: There is no "s" in Organization. NOTE: There is no "s" in Organization.
3.2.10. References 3.2.10. References
The References header field is the same as that specified in Section The References header field is the same as that specified in Section
3.6.4 of [RFC2822] with the added restrictions detailed above in 3.6.4 of [RFC5322], with the added restrictions detailed above in
Section 2.2 and those listed below: Section 2.2 and those listed below:
o The updated <msg-id> construct defined in Section 3.1.3 MUST be o The updated <msg-id> construct defined in Section 3.1.3 MUST be
used. used.
o Message identifiers MUST be separated with CFWS. o Message identifiers MUST be separated with CFWS.
RFC 5536 Netnews Article Format November 2009
o Comments in CFWS between message identifiers can cause o Comments in CFWS between message identifiers can cause
interoperability problems, so comments SHOULD NOT be generated, interoperability problems, so comments SHOULD NOT be generated but
but MUST be accepted. MUST be accepted.
references = "References:" SP [CFWS] msg-id *(CFWS msg-id) references = "References:" SP [CFWS] msg-id *(CFWS msg-id)
[CFWS] CRLF [CFWS] CRLF
3.2.11. Summary 3.2.11. Summary
The Summary header field is a short phrase summarizing the article's The Summary header field is a short phrase summarizing the article's
content. content.
summary = "Summary:" SP unstructured CRLF summary = "Summary:" SP unstructured CRLF
3.2.12. Supersedes 3.2.12. Supersedes
The Supersedes header field contains a message identifier specifying The Supersedes header field contains a message identifier specifying
an article to be superseded upon the arrival of this one. An article an article to be superseded upon the arrival of this one. An article
containing a Supersedes header field is equivalent to a "cancel" containing a Supersedes header field is equivalent to a "cancel"
[I-D.ietf-usefor-usepro] control message for the specified article, [RFC5537] control message for the specified article, followed
followed immediately by the new article without the Supersedes header immediately by the new article without the Supersedes header field.
field.
supersedes = "Supersedes:" SP *WSP msg-id *WSP CRLF supersedes = "Supersedes:" SP *WSP msg-id *WSP CRLF
NOTE: There is no "c" in Supersedes. NOTE: There is no "c" in Supersedes.
NOTE: The Supersedes header field defined here has no connection NOTE: The Supersedes header field defined here has no connection
with the Supersedes header field that sometimes appears in Email with the Supersedes header field that sometimes appears in Email
messages converted from X.400 according to [RFC2156]; in messages converted from X.400 according to [RFC2156]; in
particular, the syntax here permits only one <msg-id> in contrast particular, the syntax here permits only one <msg-id> in contrast
to the multiple <msg-id>s in that Email version. to the multiple <msg-id>s in that Email version.
3.2.13. User-Agent 3.2.13. User-Agent
The User-Agent header field contains information about the user agent The User-Agent header field contains information about the user agent
(typically a newsreader) generating the article, for statistical (typically a newsreader) generating the article, for statistical
purposes and tracing of standards violations to specific software purposes and tracing of standards violations to specific software in
needing correction. It is intended that this header field be need of correction. It is intended that this header field be
suitable for use in Email. suitable for use in Email.
user-agent = "User-Agent:" SP 1*product [CFWS] CRLF user-agent = "User-Agent:" SP 1*product [CFWS] CRLF
product = [CFWS] token [ [CFWS] "/" product-version ] product = [CFWS] token [ [CFWS] "/" product-version ]
product-version = [CFWS] token product-version = [CFWS] token
RFC 5536 Netnews Article Format November 2009
This header field MAY contain multiple <product> tokens identifying This header field MAY contain multiple <product> tokens identifying
the user agent and any subproducts which form a significant part of the user agent and any subproducts that form a significant part of
it, listed in order of their significance for identifying the it, listed in order of their significance for identifying the
application. application.
NOTE: Some of this information has previously been sent in non- NOTE: Some of this information has previously been sent in non-
standardized header fields such as X-Newsreader, X-Mailer, standardized header fields such as X-Newsreader, X-Mailer,
X-Posting-Agent, X-Http-User-Agent, and others. Once a user agent X-Posting-Agent, X-Http-User-Agent, and others. Once a user agent
generates a User-Agent header field, it should have no need to generates a User-Agent header field, it should have no need to
send these non-standard header fields. send these non-standard header fields.
NOTE: [RFC2616] describes a similar facility for the HTTP NOTE: [RFC2616] describes a similar facility for the HTTP
protocol. The Netnews article format differs in that "{" and "}" protocol. The Netnews article format differs in that "{" and "}"
are allowed in tokens (<product> and <product-version>) and are allowed in tokens (<product> and <product-version>) and
comments are permitted wherever whitespace is allowed. comments are permitted wherever white space is allowed.
3.2.14. Xref 3.2.14. Xref
The Xref header field indicates where an article was filed by the The Xref header field indicates where an article was filed by the
last news server to process it. User agents often use the last news server to process it. User agents often use the
information in the Xref header field to avoid multiple processing of information in the Xref header field to avoid multiple processing of
crossposted articles. crossposted articles.
xref = "Xref:" SP *WSP server-name xref = "Xref:" SP *WSP server-name
1*( FWS location ) *WSP CRLF 1*( FWS location ) *WSP CRLF
server-name = path-identity server-name = path-identity
location = newsgroup-name ":" article-locator location = newsgroup-name ":" article-locator
article-locator = 1*( %x21-27 / %x29-3A / %x3C-7E ) article-locator = 1*( %x21-27 / %x29-3A / %x3C-7E )
; US-ASCII printable characters ; US-ASCII printable characters
; except '(' and ';' ; except '(' and ';'
The <server-name> is included so that software can determine which The <server-name> is included so that software can determine which
news server generated the header field. The locations specify what news server generated the header field. The locations specify where
newsgroups the article was filed under (which may differ from those the article is filed -- i.e., under which newsgroups (which may
in the Newsgroups header field) and where it was filed under them. differ from those in the Newsgroups header field), and where under
The exact form of an <article-locator> is implementation-specific. those newsgroups. The exact form of an <article-locator> is
implementation-specific.
NOTE: The traditional form of an <article-locator> (as required by NOTE: The traditional form of an <article-locator> (as required by
[RFC3977]) is a decimal number, with articles in each newsgroup [RFC3977]) is a decimal number, with articles in each newsgroup
numbered consecutively starting from 1. numbered consecutively starting from 1.
RFC 5536 Netnews Article Format November 2009
3.3. Obsolete Header Fields 3.3. Obsolete Header Fields
The header fields Date-Received, Posting-Version, and Relay-Version The header fields Date-Received, Posting-Version, and Relay-Version
defined in [RFC0850], as well as Also-Control, Article-Names, defined in [RFC0850], as well as Also-Control, Article-Names,
Article-Updates, and See-Also defined in [Son-of-1036] are declared Article-Updates, and See-Also defined in [Son-of-1036] are declared
obsolete. See the cited specification documents for further obsolete. See the cited specification documents for further
information on their original use. information on their original use.
These header fields MUST NOT be generated and SHOULD be ignored. These header fields MUST NOT be generated and SHOULD be ignored.
3.3.1. Lines 3.3.1. Lines
The Lines header field indicates the number of lines in the <body> The Lines header field indicates the number of lines in the <body>
(as defined in [RFC2822]) of the article. (as defined in [RFC5322]) of the article.
lines = "Lines:" SP *WSP 1*DIGIT *WSP CRLF lines = "Lines:" SP *WSP 1*DIGIT *WSP CRLF
The line count is the number of CRLF separators in the <body>. The line count is the number of CRLF separators in the <body>.
Historically, this header field was used by the NNTP [RFC3977] Historically, this header field was used by the NNTP [RFC3977]
overview facility, but its use for this purpose is now deprecated. overview facility, but its use for this purpose is now deprecated.
As a result, this header field is to be regarded as obsolescent, and As a result, this header field is to be regarded as obsolescent, and
it is likely to be removed entirely in a future version of this it is likely to be removed entirely in a future version of this
standard. All agents SHOULD ignore it and SHOULD NOT generate it. standard. All agents SHOULD ignore it and SHOULD NOT generate it.
4. Internationalization Considerations 4. Internationalization Considerations
Internationalization of Netnews article header fields and bodies is Internationalization of Netnews article header fields and bodies is
provided using MIME mechanisms discussed in Section 2.3. Note that provided using the MIME mechanisms discussed in Section 2.3. Note
the generation of internationalized <newsgroup-name>s for use in that the generation of internationalized <newsgroup-name>s for use in
header fields is not addressed in this document. header fields is not addressed in this document.
5. Security Considerations 5. Security Considerations
The Netnews article format specified in this document does not The Netnews article format specified in this document does not
provide any security services, such as confidentiality, provide any security services, such as confidentiality,
authentication of sender, or non-repudiation. Instead, such services authentication of sender, or non-repudiation. Instead, such services
need to be layered above, using such protocols as S/MIME [RFC3851] or need to be layered above, using such protocols as S/MIME [RFC3851] or
PGP/MIME [RFC3156], or below, using secure versions of news transport PGP/MIME (Pretty Good Privacy / MIME) [RFC3156], or below, using
protocols. Additionally, several currently non-standardized secure versions of news transport protocols. Additionally, several
protocols such as [PGPVERIFY] may be standardized in the near future. currently non-standardized protocols such as [PGPVERIFY] may be
standardized in the near future.
Message identifiers (Section 3.1.3) in Netnews articles are required Message identifiers (Section 3.1.3) in Netnews articles are required
to be unique; articles may be refused (in server-to-server transfer) to be unique; articles may be refused (in server-to-server transfer)
if the identifier has already been seen. If a malicious agent can if the identifier has already been seen. If a malicious agent can
predict the identifier of an article, it can preempt the article by predict the identifier of an article, it can preempt the article by
posting its own article (possibly to a quite different group) with posting its own article (possibly to a quite different group) with
RFC 5536 Netnews Article Format November 2009
the same message identifier, thereby preventing the target article the same message identifier, thereby preventing the target article
from propagating. Therefore, agents that generate message from propagating. Therefore, agents that generate message
identifiers for Netnews articles SHOULD ensure that they are identifiers for Netnews articles SHOULD ensure that they are
unpredictable. unpredictable.
MIME security considerations are discussed in [RFC2046]. Note that MIME security considerations are discussed in [RFC2046]. Note that
the full range of encodings allowed for parameters in [RFC2046] and the full range of encodings allowed for parameters in [RFC2046] and
[RFC2231] permits constructs that simple parsers may fail to parse [RFC2231] permits constructs that simple parsers may fail to parse
correctly; examples of hard-to-parse constructs are: correctly; examples of hard-to-parse constructs are:
Content-Type: multipart/mixed Content-Type: multipart/mixed
(; boundary=foo ; xyz=");bOuNdArY*=''next%20part(") (; boundary=foo ; xyz=");bOuNdArY*=''next%20part(")
Content-Type: multipart/digest; Content-Type: multipart/digest;
boundary (not=me) = ("yes ;-) simple (foo;bar") ; x-foo = xyzzy boundary (not=me) = ("yes ;-) simple (foo;bar") ; x-foo = xyzzy
Such deficiencies in parsing may be used as part of an attack. Such deficiencies in parsing may be used as part of an attack.
Further security considerations are discussed in Further security considerations are discussed in [RFC5537].
[I-D.ietf-usefor-usepro].
6. IANA Considerations 6. IANA Considerations
IANA is requested to register the following header fields in the IANA has registered the following header fields in the Permanent
Permanent Message Header Field Repository, in accordance with the Message Header Field Repository, in accordance with the procedures
procedures set out in [RFC3864]. set out in [RFC3864].
Header field name: Also-Control Header field name: Also-Control
Applicable protocol: netnews Applicable protocol: netnews
Status: obsoleted Status: obsoleted
Author/change controller: IETF Author/change controller: IETF
Specification document(s): [Son-of-1036] (Section 6.15) Specification document(s): [Son-of-1036] (Section 6.15)
Header field name: Approved Header field name: Approved
Applicable protocol: netnews Applicable protocol: netnews
Status: standard Status: standard
Author/change controller: IETF Author/change controller: IETF
Specification document(s): This document (Section 3.2.1) Specification document(s): This document (Section 3.2.1)
Header field name: Archive Header field name: Archive
Applicable protocol: netnews Applicable protocol: netnews
Status: standard Status: standard
Author/change controller: IETF Author/change controller: IETF
Specification document(s): This document (Section 3.2.2) Specification document(s): This document (Section 3.2.2)
RFC 5536 Netnews Article Format November 2009
Header field name: Article-Names Header field name: Article-Names
Applicable protocol: netnews Applicable protocol: netnews
Status: obsoleted Status: obsoleted
Author/change controller: IETF Author/change controller: IETF
Specification document(s): [Son-of-1036] (Section 6.17) Specification document(s): [Son-of-1036] (Section 6.17)
Header field name: Article-Updates Header field name: Article-Updates
Applicable protocol: netnews Applicable protocol: netnews
Status: obsoleted Status: obsoleted
Author/change controller: IETF Author/change controller: IETF
Specification document(s): [Son-of-1036] (Section 6.18) Specification document(s): [Son-of-1036] (Section 6.18)
Header field name: Comments Header field name: Comments
Applicable protocol: netnews Applicable protocol: netnews
Status: standard Status: standard
Author/change controller: IETF Author/change controller: IETF
Specification document(s): This document (Section 3.2), Specification document(s): This document (Section 3.2),
[RFC2822] (Section 3.6.5) [RFC5322] (Section 3.6.5)
Header field name: Control Header field name: Control
Applicable protocol: netnews Applicable protocol: netnews
Status: standard Status: standard
Author/change controller: IETF Author/change controller: IETF
Specification document(s): This document (Section 3.2.3) Specification document(s): This document (Section 3.2.3)
Header field name: Date Header field name: Date
Applicable protocol: netnews Applicable protocol: netnews
Status: standard Status: standard
Author/change controller: IETF Author/change controller: IETF
Specification document(s): This document (Section 3.1.1), Specification document(s): This document (Section 3.1.1),
[RFC2822] (Section 3.6.1) [RFC5322] (Section 3.6.1)
Header field name: Date-Received Header field name: Date-Received
Applicable protocol: netnews Applicable protocol: netnews
Status: obsoleted Status: obsoleted
Author/change controller: IETF Author/change controller: IETF
Specification document(s): [RFC0850] (Section 2.2.4) Specification document(s): [RFC0850] (Section 2.2.4)
Header field name: Distribution Header field name: Distribution
Applicable protocol: netnews Applicable protocol: netnews
Status: standard Status: standard
Author/change controller: IETF Author/change controller: IETF
Specification document(s): This document (Section 3.2.4) Specification document(s): This document (Section 3.2.4)
RFC 5536 Netnews Article Format November 2009
Header field name: Expires Header field name: Expires
Applicable protocol: netnews Applicable protocol: netnews
Status: standard Status: standard
Author/change controller: IETF Author/change controller: IETF
Specification document(s): This document (Section 3.2.5) Specification document(s): This document (Section 3.2.5)
Header field name: Followup-To Header field name: Followup-To
Applicable protocol: netnews Applicable protocol: netnews
Status: standard Status: standard
Author/change controller: IETF Author/change controller: IETF
Specification document(s): This document (Section 3.2.6) Specification document(s): This document (Section 3.2.6)
Header field name: From Header field name: From
Applicable protocol: netnews Applicable protocol: netnews
Status: standard Status: standard
Author/change controller: IETF Author/change controller: IETF
Specification document(s): This document (Section 3.1.2), Specification document(s): This document (Section 3.1.2),
[RFC2822] (Section 3.6.2) [RFC5322] (Section 3.6.2)
Header field name: Injection-Date Header field name: Injection-Date
Applicable protocol: netnews Applicable protocol: netnews
Status: standard Status: standard
Author/change controller: IETF Author/change controller: IETF
Specification document(s): This document (Section 3.2.7) Specification document(s): This document (Section 3.2.7)
Header field name: Injection-Info Header field name: Injection-Info
Applicable protocol: netnews Applicable protocol: netnews
Status: standard Status: standard
Author/change controller: IETF Author/change controller: IETF
Specification document(s): This document (Section 3.2.8) Specification document(s): This document (Section 3.2.8)
Header field name: Keywords Header field name: Keywords
Applicable protocol: netnews Applicable protocol: netnews
Status: standard Status: standard
Author/change controller: IETF Author/change controller: IETF
Specification document(s): This document (Section 3.2), Specification document(s): This document (Section 3.2),
[RFC2822] (Section 3.6.5) [RFC5322] (Section 3.6.5)
Header field name: Lines Header field name: Lines
Applicable protocol: netnews Applicable protocol: netnews
Status: deprecated Status: deprecated
Author/change controller: IETF Author/change controller: IETF
Specification document(s): This document (Section 3.3.1) Specification document(s): This document (Section 3.3.1)
Related information: [RFC3977] (Section 8.1) Related information: [RFC3977] (Section 8.1)
RFC 5536 Netnews Article Format November 2009
Header field name: Message-ID Header field name: Message-ID
Applicable protocol: netnews Applicable protocol: netnews
Status: standard Status: standard
Author/change controller: IETF Author/change controller: IETF
Specification document(s): This document (Section 3.1.3) Specification document(s): This document (Section 3.1.3)
Related information: [RFC2822] (Section 3.6.4) Related information: [RFC5322] (Section 3.6.4)
Header field name: Newsgroups Header field name: Newsgroups
Applicable protocol: netnews Applicable protocol: netnews
Status: standard Status: standard
Author/change controller: IETF Author/change controller: IETF
Specification document(s): This document (Section 3.1.4) Specification document(s): This document (Section 3.1.4)
Header field name: NNTP-Posting-Date Header field name: NNTP-Posting-Date
Applicable protocol: netnews Applicable protocol: netnews
Status: obsoleted Status: obsoleted
skipping to change at page 33, line 16 skipping to change at page 30, line 5
Status: standard Status: standard
Author/change controller: IETF Author/change controller: IETF
Specification document(s): This document (Section 3.1.5) Specification document(s): This document (Section 3.1.5)
Header field name: Posting-Version Header field name: Posting-Version
Applicable protocol: netnews Applicable protocol: netnews
Status: obsoleted Status: obsoleted
Author/change controller: IETF Author/change controller: IETF
Specification document(s): [RFC0850] (Section 2.1.2) Specification document(s): [RFC0850] (Section 2.1.2)
RFC 5536 Netnews Article Format November 2009
Header field name: References Header field name: References
Applicable protocol: netnews Applicable protocol: netnews
Status: standard Status: standard
Author/change controller: IETF Author/change controller: IETF
Specification document(s): This document (Section 3.2.10), Specification document(s): This document (Section 3.2.10),
[RFC2822] (Section 3.6.4) [RFC5322] (Section 3.6.4)
Header field name: Relay-Version Header field name: Relay-Version
Applicable protocol: netnews Applicable protocol: netnews
Status: obsoleted Status: obsoleted
Author/change controller: IETF Author/change controller: IETF
Specification document(s): [RFC0850] (Section 2.1.1) Specification document(s): [RFC0850] (Section 2.1.1)
Header field name: Reply-To Header field name: Reply-To
Applicable protocol: netnews Applicable protocol: netnews
Status: standard Status: standard
Author/change controller: IETF Author/change controller: IETF
Specification document(s): This document (Section 3.2), Specification document(s): This document (Section 3.2),
[RFC2822] (Section 3.6.2) [RFC5322] (Section 3.6.2)
Header field name: See-Also Header field name: See-Also
Applicable protocol: netnews Applicable protocol: netnews
Status: obsoleted Status: obsoleted
Author/change controller: IETF Author/change controller: IETF
Specification document(s): [Son-of-1036] (Section 6.16) Specification document(s): [Son-of-1036] (Section 6.16)
Header field name: Sender Header field name: Sender
Applicable protocol: netnews Applicable protocol: netnews
Status: standard Status: standard
Author/change controller: IETF Author/change controller: IETF
Specification document(s): This document (Section 3.2), Specification document(s): This document (Section 3.2),
[RFC2822] (Section 3.6.2) [RFC5322] (Section 3.6.2)
Header field name: Subject Header field name: Subject
Applicable protocol: netnews Applicable protocol: netnews
Status: standard Status: standard
Author/change controller: IETF Author/change controller: IETF
Specification document(s): This document (Section 3.1.6), Specification document(s): This document (Section 3.1.6),
[RFC2822] (Section 3.6.5) [RFC5322] (Section 3.6.5)
Header field name: Summary Header field name: Summary
Applicable protocol: netnews Applicable protocol: netnews
Status: standard Status: standard
Author/change controller: IETF Author/change controller: IETF
Specification document(s): This document (Section 3.2.11) Specification document(s): This document (Section 3.2.11)
RFC 5536 Netnews Article Format November 2009
Header field name: Supersedes Header field name: Supersedes
Applicable protocol: netnews Applicable protocol: netnews
Status: standard Status: standard
Author/change controller: IETF Author/change controller: IETF
Specification document(s): This document (Section 3.2.12) Specification document(s): This document (Section 3.2.12)
Header field name: User-Agent Header field name: User-Agent
Applicable protocol: netnews Applicable protocol: netnews
Status: standard Status: standard
Author/change controller: IETF Author/change controller: IETF
skipping to change at page 35, line 9 skipping to change at page 31, line 30
Header field name: Xref Header field name: Xref
Applicable protocol: netnews Applicable protocol: netnews
Status: standard Status: standard
Author/change controller: IETF Author/change controller: IETF
Specification document(s): This document (Section 3.2.14) Specification document(s): This document (Section 3.2.14)
7. References 7. References
7.1. Normative References 7.1. Normative References
[I-D.ietf-usefor-usepro] [RFC2045] Freed, N. and N. Borenstein, "Multipurpose Internet
Allbery, R. and C. Lindsey, "Netnews Architecture and Mail Extensions (MIME) Part One: Format of Internet
Protocols", draft-ietf-usefor-usepro-07 (work in Message Bodies", RFC 2045, November 1996.
progress), January 2007.
[RFC2045] Freed, N. and N. Borenstein, "Multipurpose Internet Mail [RFC2046] Freed, N. and N. Borenstein, "Multipurpose Internet
Extensions (MIME) Part One: Format of Internet Message Mail Extensions (MIME) Part Two: Media Types",
Bodies", RFC 2045, November 1996. RFC 2046, November 1996.
[RFC2046] Freed, N. and N. Borenstein, "Multipurpose Internet Mail [RFC2047] Moore, K., "MIME (Multipurpose Internet Mail
Extensions (MIME) Part Two: Media Types", RFC 2046, Extensions) Part Three: Message Header Extensions for
November 1996. Non-ASCII Text", RFC 2047, November 1996.
[RFC2047] Moore, K., "MIME (Multipurpose Internet Mail Extensions) [RFC2049] Freed, N. and N. Borenstein, "Multipurpose Internet
Part Three: Message Header Extensions for Non-ASCII Text", Mail Extensions (MIME) Part Five: Conformance Criteria
RFC 2047, November 1996. and Examples", RFC 2049, November 1996.
[RFC2049] Freed, N. and N. Borenstein, "Multipurpose Internet Mail [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Extensions (MIME) Part Five: Conformance Criteria and Requirement Levels", BCP 14, RFC 2119, March 1997.
Examples", RFC 2049, November 1996.
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate [RFC2183] Troost, R., Dorner, S., and K. Moore, "Communicating
Requirement Levels", BCP 14, RFC 2119, March 1997. Presentation Information in Internet Messages: The
Content-Disposition Header Field", RFC 2183,
August 1997.
[RFC2183] Troost, R., Dorner, S., and K. Moore, "Communicating RFC 5536 Netnews Article Format November 2009
Presentation Information in Internet Messages: The
Content-Disposition Header Field", RFC 2183, August 1997.
[RFC2231] Freed, N. and K. Moore, "MIME Parameter Value and Encoded [RFC2231] Freed, N. and K. Moore, "MIME Parameter Value and
Word Extensions: Character Sets, Languages, and Encoded Word Extensions: Character Sets, Languages,
Continuations", RFC 2231, November 1997. and Continuations", RFC 2231, November 1997.
[RFC2822] Resnick, P., "Internet Message Format", RFC 2822, [RFC3282] Alvestrand, H., "Content Language Headers", RFC 3282,
April 2001. May 2002.
[RFC3282] Alvestrand, H., "Content Language Headers", RFC 3282, [RFC3986] Berners-Lee, T., Fielding, R., and L. Masinter,
May 2002. "Uniform Resource Identifier (URI): Generic Syntax",
STD 66, RFC 3986, January 2005.
[RFC3986] Berners-Lee, T., Fielding, R., and L. Masinter, "Uniform [RFC5234] Crocker, D. and P. Overell, "Augmented BNF for Syntax
Resource Identifier (URI): Generic Syntax", STD 66, Specifications: ABNF", STD 68, RFC 5234, January 2008.
RFC 3986, January 2005.
[RFC4234] Crocker, D., Ed. and P. Overell, "Augmented BNF for Syntax [RFC5322] Resnick, P., Ed., "Internet Message Format", RFC 5322,
Specifications: ABNF", RFC 4234, October 2005. October 2008.
[RFC5537] Allbery, R., Ed. and C. Lindsey, "Netnews Architecture
and Protocols", RFC 5537, November 2009.
7.2. Informative References 7.2. Informative References
[Errata] "RFC Editor Errata", [Errata] "RFC Editor Errata",
http://www.rfc-editor.org/errata.html. <http://www.rfc-editor.org/errata.php>.
[I-D.ietf-usefor-useage] [ISO3166-1] International Organization for Standardization, "ISO
Lindsey, C., "Usenet Best Practice", 3166-1:1997. Codes for the representation of names of
draft-ietf-usefor-useage-01 (work in progress), countries and their subdivisions -- Part 1: Country
March 2005. codes", 1997.
[ISO3166-1] [PGPVERIFY] Lawrence, D., "Authentication of Usenet Group Changes
International Organization for Standardization, "ISO 3166- (pgpverify)", June 1999,
1:1997. Codes for the representation of names of countries <ftp://ftp.isc.org/pub/pgpcontrol/README.html>.
and their subdivisions -- Part 1: Country codes", 1997.
[PGPVERIFY] [RFC0822] Crocker, D., "Standard for the format of ARPA Internet
Lawrence, D., "PGPverify", text messages", STD 11, RFC 822, August 1982.
ftp://ftp.isc.org/pub/pgpcontrol/README.html, June 1999.
[RFC0822] Crocker, D., "Standard for the format of ARPA Internet [RFC0850] Horton, M., "Standard for interchange of USENET
text messages", STD 11, RFC 822, August 1982. messages", RFC 850, June 1983.
[RFC0850] Horton, M., "Standard for interchange of USENET messages", [RFC1036] Horton, M. and R. Adams, "Standard for interchange of
RFC 850, June 1983. USENET messages", RFC 1036, December 1987.
[RFC1036] Horton, M. and R. Adams, "Standard for interchange of [RFC2156] Kille, S., "MIXER (Mime Internet X.400 Enhanced
USENET messages", RFC 1036, December 1987. Relay): Mapping between X.400 and RFC 822/MIME",
RFC 2156, January 1998.
[RFC2156] Kille, S., "MIXER (Mime Internet X.400 Enhanced Relay): RFC 5536 Netnews Article Format November 2009
Mapping between X.400 and RFC 822/MIME", RFC 2156,
January 1998.
[RFC2616] Fielding, R., Gettys, J., Mogul, J., Frystyk, H., [RFC2616] Fielding, R., Gettys, J., Mogul, J., Frystyk, H.,
Masinter, L., Leach, P., and T. Berners-Lee, "Hypertext Masinter, L., Leach, P., and T. Berners-Lee,
Transfer Protocol -- HTTP/1.1", RFC 2616, June 1999. "Hypertext Transfer Protocol -- HTTP/1.1", RFC 2616,
June 1999.
[RFC2980] Barber, S., "Common NNTP Extensions", RFC 2980, [RFC2822] Resnick, P., "Internet Message Format", RFC 2822,
October 2000. April 2001.
[RFC3156] Elkins, M., Del Torto, D., Levien, R., and T. Roessler, [RFC2980] Barber, S., "Common NNTP Extensions", RFC 2980,
"MIME Security with OpenPGP", RFC 3156, August 2001. October 2000.
[RFC3696] Klensin, J., "Application Techniques for Checking and [RFC3156] Elkins, M., Del Torto, D., Levien, R., and T.
Transformation of Names", RFC 3696, February 2004. Roessler, "MIME Security with OpenPGP", RFC 3156,
August 2001.
[RFC3851] Ramsdell, B., "Secure/Multipurpose Internet Mail [RFC3696] Klensin, J., "Application Techniques for Checking and
Extensions (S/MIME) Version 3.1 Message Specification", Transformation of Names", RFC 3696, February 2004.
RFC 3851, July 2004.
[RFC3864] Klyne, G., Nottingham, M., and J. Mogul, "Registration [RFC3851] Ramsdell, B., "Secure/Multipurpose Internet Mail
Procedures for Message Header Fields", BCP 90, RFC 3864, Extensions (S/MIME) Version 3.1 Message
September 2004. Specification", RFC 3851, July 2004.
[RFC3977] Feather, C., "Network News Transfer Protocol (NNTP)", [RFC3864] Klyne, G., Nottingham, M., and J. Mogul, "Registration
RFC 3977, October 2006. Procedures for Message Header Fields", BCP 90,
RFC 3864, September 2004.
[Son-of-1036] [RFC3977] Feather, C., "Network News Transfer Protocol (NNTP)",
Spencer, H., "News Article Format and Transmission", RFC 3977, October 2006.
ftp://ftp.zoo.toronto.edu/pub/news.txt.Z, June 1994.
[Son-of-1036] Spencer, H., "Son of 1036: News Article Format and
Transmission", Work in Progress, May 2009.
[USEAGE] Lindsey, C., "Usenet Best Practice", Work in Progress,
March 2005.
RFC 5536 Netnews Article Format November 2009
Appendix A. Acknowledgments Appendix A. Acknowledgments
As this document is the result of an eight year effort, the number of As this document is the result of an eight-year effort, the number of
people that have contributed to its content are too numerous to people that have contributed to its content are too numerous to
mention individually. Many thanks go out to all past and present mention individually. Many thanks go out to all past and present
members of the USEFOR Working Group of the Internet Engineering Task members of the USEFOR Working Group of the Internet Engineering Task
Force (IETF) and its accompanying mailing list. Force (IETF) and its accompanying mailing list.
Appendix B. Differences from RFC 1036 and its derivatives Appendix B. Differences from RFC 1036 and Its Derivatives
This appendix contains a list of changes that have been made in the This appendix contains a list of changes that have been made in the
Netnews Article Format from earlier standards, specifically Netnews article format from earlier standards, specifically
[RFC1036]. [RFC1036].
o The [RFC2822] conventions for parenthesis-enclosed <comment>s in o The [RFC5322] conventions for parenthesis-enclosed <comment>s in
header fields are supported in all newly defined header fields and header fields are supported in all newly defined header fields and
in header fields inherited from [RFC2822]. They are, however, in header fields inherited from [RFC5322]. They are, however,
still disallowed for performance and/or compatibility reasons in still disallowed for performance and/or compatibility reasons in
the Control, Distribution, Followup-To, Lines, Message-ID, the Control, Distribution, Followup-To, Lines, Message-ID,
Newsgroups, Path, Supersedes, and Xref header fields. Newsgroups, Path, Supersedes, and Xref header fields.
o Multiple addresses are allowed in the From header field. o Multiple addresses are allowed in the From header field.
o [FWS] is permitted in Newsgroups header fields. o [FWS] is permitted in Newsgroups header fields.
o An enhanced syntax for the Path header field enables the injection o An enhanced syntax for the Path header field enables the injection
point of, and the route taken by, an article to be determined with point of, and the route taken by, an article to be determined with
skipping to change at page 39, line 45 skipping to change at page 35, line 5
o There are several new optional header fields defined, notably o There are several new optional header fields defined, notably
Archive, Injection-Info, and User-Agent, leading to increased Archive, Injection-Info, and User-Agent, leading to increased
functionality. functionality.
o Certain header fields, notably Lines, have been deprecated or made o Certain header fields, notably Lines, have been deprecated or made
obsolete (Section 3.3). obsolete (Section 3.3).
o The convention to interpret subjects starting with the word "cmsg" o The convention to interpret subjects starting with the word "cmsg"
as a control message was removed. as a control message was removed.
RFC 5536 Netnews Article Format November 2009
o There are numerous other small changes, clarifications, and o There are numerous other small changes, clarifications, and
enhancements. enhancements.
Appendix C. Differences from RFC 2822 Appendix C. Differences from RFC 5322
This appendix lists the differences between the syntax allowed by the This appendix lists the differences between the syntax allowed by the
Netnews Article Format (this document) as compared to the Internet Netnews article format (this document) as compared to the Internet
Message Format, as specified in [RFC2822]. Message Format, as specified in [RFC5322].
The Netnews article format is a strict subset of the Internet Message The Netnews article format is a strict subset of the Internet Message
Format; all Netnews articles conform to the syntax of [RFC2822]. Format; all Netnews articles conform to the syntax of [RFC5322].
The following restrictions are important: The following restrictions are important:
o A SP (space) is REQUIRED after the colon (':') following a header o A SP (space) is REQUIRED after the colon (':') following a header
field name. field name.
o A more restricted syntax of <msg-id> (to be used by the o A slightly restricted syntax of <msg-id> (to be used by the
Message-ID, References, and Supersedes header fields) is defined. Message-ID, References, and Supersedes header fields) is defined.
o The length of a <msg-id> MUST NOT exceed 250 octets. o The length of a <msg-id> MUST NOT exceed 250 octets.
o Comments are not allowed in the Message-ID header field. o Comments are not allowed in the Message-ID header field.
o The CFWS between <msg-id>s in the References header field is not o The CFWS between <msg-id>s in the References header field is not
optional. optional.
o It is legal for a parser to reject obsolete syntax, except that: o It is legal for a parser to reject obsolete syntax, except that:
skipping to change at page 41, line 5 skipping to change at page 36, line 5
* The <obs-phrase> construct MUST be accepted. * The <obs-phrase> construct MUST be accepted.
* The obsolete <zone> "GMT" MUST be accepted within a * The obsolete <zone> "GMT" MUST be accepted within a
<date-time>. <date-time>.
o Every line of a header field body (including the first and any o Every line of a header field body (including the first and any
that are subsequently folded) MUST contain at least one non- that are subsequently folded) MUST contain at least one non-
whitespace character. This means that an empty header field body whitespace character. This means that an empty header field body
is illegal. is illegal.
RFC 5536 Netnews Article Format November 2009
Authors' Addresses Authors' Addresses
Kenneth Murchison (editor) Kenneth Murchison (editor)
Carnegie Mellon University Carnegie Mellon University
5000 Forbes Avenue 5000 Forbes Avenue
Cyert Hall 285 Cyert Hall 285
Pittsburgh, PA 15213 Pittsburgh, PA 15213
U.S.A. U.S.A.
Phone: +1 412 268 2638 Phone: +1 412 268 2638
Email: murch@andrew.cmu.edu EMail: murch@andrew.cmu.edu
Charles H. Lindsey Charles H. Lindsey
University of Manchester University of Manchester
5 Clerewood Avenue 5 Clerewood Avenue
Heald Green Heald Green
Cheadle Cheadle
Cheshire SK8 3JU Cheshire SK8 3JU
U.K. U.K.
Phone: +44 161 436 6131 Phone: +44 161 436 6131
Email: chl@clerew.man.ac.uk EMail: chl@clerew.man.ac.uk
Dan Kohn Dan Kohn
FlyDash, Inc. Healing Thresholds
1741 Sunset Dr. 211 N End Ave Apt 22E
Pacific Grove, CA 93950 New York, NY 10282
U.S.A. U.S.A.
Phone: +1 415 233 1000 Phone: +1 415 233 1000
Email: dan@dankohn.com EMail: dan@dankohn.com
Full Copyright Statement
Copyright (C) The IETF Trust (2007).
This document is subject to the rights, licenses and restrictions
contained in BCP 78, and except as set forth therein, the authors
retain all their rights.
This document and the information contained herein are provided on an
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THE INTERNET ENGINEERING TASK FORCE DISCLAIM ALL WARRANTIES, EXPRESS
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WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.
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this document or the extent to which any license under such rights
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on the procedures with respect to rights in RFC documents can be
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Copies of IPR disclosures made to the IETF Secretariat and any
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Acknowledgment
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