draft-ietf-usefor-article-09.txt   draft-ietf-usefor-article-10.txt 
INTERNET-DRAFT Charles H. Lindsey INTERNET-DRAFT Charles H. Lindsey
Usenet Format Working Group University of Manchester Usenet Format Working Group University of Manchester
February 2003 April 2003
News Article Format News Article Format
<draft-ietf-usefor-article-09.txt> <draft-ietf-usefor-article-10.txt>
Status of this Memo Status of this Memo
This document is an Internet-Draft and is in full conformance with This document is an Internet-Draft and is in full conformance with
all provisions of Section 10 of RFC 2026. all provisions of Section 10 of RFC 2026.
Internet-Drafts are working documents of the Internet Engineering Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF), its areas, and its working groups. Note that Task Force (IETF), its areas, and its working groups. Note that
other groups may also distribute working documents as Internet- other groups may also distribute working documents as Internet-
Drafts. Drafts.
skipping to change at page 1, line 50 skipping to change at page 1, line 50
Since the 1980s, Usenet has grown explosively, and many Internet and Since the 1980s, Usenet has grown explosively, and many Internet and
non-Internet sites now participate. In addition, the Netnews non-Internet sites now participate. In addition, the Netnews
technology is now in widespread use for other purposes. technology is now in widespread use for other purposes.
Backward compatibility has been a major goal of this endeavour, but Backward compatibility has been a major goal of this endeavour, but
where this standard and earlier documents or practices conflict, this where this standard and earlier documents or practices conflict, this
standard should be followed. In most such cases, current practice is standard should be followed. In most such cases, current practice is
already compatible with these changes. already compatible with these changes.
[This draft is derived from draft-09 by removing all the
Internationalization features (i.e. those involving the use of the UTF-8
charset in headers). This is being done so as to facilitate publishing
those features, or similar ones, as an experimental protocol at a later
stage.
It is also intended to split it into two or more documents. Thus this
present draft is but an intermediate stage in an ongoing development
News Article Format April 2003
process.]
[The use of the words "this standard" within this document when [The use of the words "this standard" within this document when
referring to itself does not imply that this draft yet has pretensions referring to itself does not imply that this draft yet has pretensions
to be a standard, but rather indicates what will become the case if and to be a standard, but rather indicates what will become the case if and
when it is accepted as an RFC with the status of a proposed or draft when it is accepted as an RFC with the status of a proposed or draft
standard.] standard.]
News Article Format February 2003
[Remarks enclosed in square brackets and aligned with the left margin, [Remarks enclosed in square brackets and aligned with the left margin,
such as this one, are not part of this draft, but are editorial notes to such as this one, are not part of this draft, but are editorial notes to
explain matters amongst ourselves, or to point out alternatives, or to explain matters amongst ourselves, or to point out alternatives, or to
assist the RFC Editor.] assist the RFC Editor.]
[In this draft, references to [NNTP] are to be replaced by [RFC 977], or [In this draft, references to [NNTP] are to be replaced by [RFC 977], or
else by references to the RFC arising from the series of drafts draft- else by references to the RFC arising from the series of drafts draft-
ietf-nntpext-base-*.txt, in the event that such RFC has been accepted at ietf-nntpext-base-*.txt, in the event that such RFC has been accepted at
the time this document is published. Likewise, if may be possible to the time this document is published. Likewise, if may be possible to
replace references to [RFC 2279] by references to [RFC 2279bis].] replace references to [RFC 2279] by references to [RFC 2279bis].]
[Please note that this Draft is subject to change as regards the extent
to which the charset UTF-8 is to be used in headers, or even whether it
is used at all. It is published at this time to give a snapshot of the
current state of the project.
It is also intended to split it into two documents, one the standard
proper and the other an informational document setting out best current
practice.]
Table of Contents Table of Contents
1. Introduction .................................................. 6 1. Introduction .................................................. 6
1.1. Basic Concepts ............................................ 6 1.1. Basic Concepts ............................................ 6
1.2. Objectives ................................................ 7 1.2. Objectives ................................................ 7
1.3. Historical Outline ........................................ 7 1.3. Historical Outline ........................................ 7
1.4. Transport ................................................. 7 1.4. Transport ................................................. 7
2. Definitions, Notations and Conventions ........................ 8 2. Definitions, Notations and Conventions ........................ 8
2.1. Definitions ............................................... 8 2.1. Definitions ............................................... 8
2.2. Textual Notations ......................................... 9 2.2. Textual Notations ......................................... 9
2.3. Relation To Email and MIME ................................ 11 2.3. Relation To Email and MIME ................................ 11
2.4. Syntax .................................................... 11 2.4. Syntax .................................................... 11
2.4.1. Syntax Notation ....................................... 11 2.4.1. Syntax Notation ....................................... 11
2.4.2. Syntax adapted from Email and MIME .................... 11 2.4.2. Syntax adapted from Email and MIME .................... 11
2.4.3. Syntax copied from other standards .................... 13 2.4.3. Syntax copied from other standards .................... 12
2.5. Language .................................................. 14 2.5. Language .................................................. 14
3. Changes to the existing protocols ............................. 15 3. Changes to the existing protocols ............................. 14
3.1. Principal Changes ......................................... 15 3.1. Principal Changes ......................................... 15
3.2. Transitional Arrangements ................................. 15 3.2. Transitional Arrangements ................................. 15
4. Basic Format .................................................. 17 4. Basic Format .................................................. 16
4.1. Syntax of News Articles ................................... 17 4.1. Syntax of News Articles ................................... 16
4.2. Headers ................................................... 18 4.2. Headers ................................................... 17
4.2.1. Naming of Headers ..................................... 18 4.2.1. Naming of Headers ..................................... 17
4.2.2. MIME-style Parameters ................................. 19 4.2.2. MIME-style Parameters ................................. 18
4.2.3. White Space and Continuations ......................... 20 4.2.3. White Space and Continuations ......................... 19
4.2.4. Comments .............................................. 21 4.2.4. Comments .............................................. 20
4.2.5. Header Properties ..................................... 22 4.2.5. Header Properties ..................................... 21
4.2.5.1. Experimental Headers .............................. 22 4.2.5.1. Experimental Headers .............................. 21
4.2.5.2. Inheritable Headers ............................... 22 4.2.5.2. Inheritable Headers ............................... 22
4.2.5.3. Variant Headers ................................... 23 4.2.5.3. Variant Headers ................................... 22
4.2.6. Undesirable Headers ................................... 23 4.2.6. Undesirable Headers ................................... 22
4.3. Body ...................................................... 23 4.3. Body ...................................................... 23
4.3.1. Body Format Issues .................................... 23 4.3.1. Body Format Issues .................................... 23
4.3.2. Body Conventions ...................................... 24 4.3.2. Body Conventions ...................................... 23
News Article Format February 2003 4.4. Characters and Character Sets ............................. 25
News Article Format April 2003
4.4. Characters and Character Sets ............................. 26
4.4.1. Character Sets within Article Headers ................. 26 4.4.1. Character Sets within Article Headers ................. 26
4.4.2. Character Sets within Article Bodies .................. 29 4.4.2. Character Sets within Article Bodies .................. 26
4.4.3. The NEWS-8BIT-HEADERS IMAP Extension .................. 29 4.5. Size Limits ............................................... 26
4.5. Size Limits ............................................... 30 4.6. Example ................................................... 27
4.6. Example ................................................... 31 5. Mandatory Headers ............................................. 28
5. Mandatory Headers ............................................. 32 5.1. Date ...................................................... 28
5.1. Date ...................................................... 32 5.1.1. Examples .............................................. 29
5.1.1. Examples .............................................. 33 5.2. From ...................................................... 29
5.2. From ...................................................... 33 5.2.1. Examples: ............................................ 30
5.2.1. Examples: ............................................ 34 5.3. Message-ID ................................................ 30
5.3. Message-ID ................................................ 34 5.4. Subject ................................................... 31
5.4. Subject ................................................... 35 5.4.1. Examples .............................................. 32
5.4.1. Examples .............................................. 36 5.5. Newsgroups ................................................ 33
5.5. Newsgroups ................................................ 36 5.5.1. Forbidden newsgroup-names ............................. 35
5.5.1. Forbidden newsgroup-names ............................. 41 5.6. Path ...................................................... 35
5.5.2. Encoded newsgroup-names ............................... 41 5.6.1. Format ................................................ 36
5.6. Path ...................................................... 42 5.6.2. Adding a path-identity to the Path-header ............. 36
5.6.1. Format ................................................ 42 5.6.3. The tail-entry ........................................ 38
5.6.2. Adding a path-identity to the Path-header ............. 43 5.6.4. Path-Delimiter Summary ................................ 38
5.6.3. The tail-entry ........................................ 44 5.6.5. Suggested Verification Methods ........................ 39
5.6.4. Path-Delimiter Summary ................................ 45 5.6.6. Example ............................................... 39
5.6.5. Suggested Verification Methods ........................ 46 6. Optional Headers .............................................. 40
5.6.6. Example ............................................... 46 6.1. Reply-To .................................................. 40
6. Optional Headers .............................................. 47 6.1.1. Examples .............................................. 41
6.1. Reply-To .................................................. 47 6.2. Sender .................................................... 41
6.1.1. Examples .............................................. 47 6.3. Organization .............................................. 41
6.2. Sender .................................................... 48 6.4. Keywords .................................................. 41
6.3. Organization .............................................. 48 6.5. Summary ................................................... 42
6.4. Keywords .................................................. 48 6.6. Distribution .............................................. 42
6.5. Summary ................................................... 48 6.7. Followup-To ............................................... 43
6.6. Distribution .............................................. 49 6.8. Mail-Copies-To ............................................ 44
6.7. Followup-To ............................................... 50 6.9. Posted-And-Mailed ......................................... 45
6.8. Mail-Copies-To ............................................ 50 6.10. References ............................................... 45
6.9. Posted-And-Mailed ......................................... 52 6.10.1. Examples ............................................. 46
6.10. References ............................................... 52 6.11. Expires .................................................. 46
6.10.1. Examples ............................................. 53 6.12. Archive .................................................. 47
6.11. Expires .................................................. 53 6.13. Control .................................................. 47
6.12. Archive .................................................. 53 6.14. Approved ................................................. 48
6.13. Control .................................................. 54 6.15. Supersedes ............................................... 49
6.14. Approved ................................................. 55 6.16. Xref ..................................................... 49
6.15. Supersedes ............................................... 55 6.17. Lines .................................................... 50
6.16. Xref ..................................................... 56 6.18. User-Agent ............................................... 50
6.17. Lines .................................................... 57 6.18.1. Examples ............................................. 51
6.18. User-Agent ............................................... 57 6.19. Injector-Info ............................................ 52
6.18.1. Examples ............................................. 58 6.19.1. Usage of Injector-Info-parameters .................... 53
6.19. Injector-Info ............................................ 58 6.19.1.1. The posting-host-parameter ....................... 54
6.19.1. Usage of Injector-Info-parameters .................... 60 6.19.1.2. The posting-account-parameter .................... 54
6.19.1.1. The posting-host-parameter ....................... 61 6.19.1.3. The posting-sender-parameter ..................... 54
6.19.1.2. The posting-account-parameter .................... 61 6.19.1.4. The posting-logging-parameter .................... 55
6.19.1.3. The posting-sender-parameter ..................... 61 6.19.1.5. The posting-date-parameter ....................... 55
6.19.1.4. The posting-logging-parameter .................... 61 6.19.2. Example .............................................. 55
6.19.1.5. The posting-date-parameter ....................... 62 6.20. Complaints-To ............................................ 55
6.19.2. Example .............................................. 62 6.21. MIME headers ............................................. 56
News Article Format February 2003 6.21.1. Syntax ............................................... 56
News Article Format April 2003
6.20. Complaints-To ............................................ 62 6.21.2. Content-Type ......................................... 56
6.21. MIME headers ............................................. 62 6.21.2.1. Message/partial .................................. 57
6.21.1. Syntax ............................................... 62 6.21.2.2. Message/rfc822 ................................... 57
6.21.2. Content-Type ......................................... 63 6.21.2.3. Message/external-body ............................ 58
6.21.2.1. Message/partial .................................. 64 6.21.2.4. Multipart types .................................. 58
6.21.2.2. Message/rfc822 ................................... 64 6.21.3. Content-Transfer-Encoding ............................ 58
6.21.2.3. Message/external-body ............................ 65 6.21.4. Character Sets ....................................... 60
6.21.2.4. Multipart types .................................. 65 6.21.5. Content Disposition .................................. 60
6.21.3. Content-Transfer-Encoding ............................ 65 6.21.6. Definition of some new Content-Types ................. 60
6.21.4. Character Sets ....................................... 67 6.21.6.1. Application/news-transmission .................... 60
6.21.5. Content Disposition .................................. 67 6.21.6.2. Message/news obsoleted ........................... 62
6.21.6. Definition of some new Content-Types ................. 67 6.22. Obsolete Headers ......................................... 62
6.21.6.1. Application/news-transmission .................... 67 7. Control Messages .............................................. 62
6.21.6.2. Message/news obsoleted ........................... 68 7.1. Digital Signature of Headers .............................. 63
6.22. Obsolete Headers ......................................... 69 7.2. Group Control Messages .................................... 63
7. Control Messages .............................................. 69 7.2.1. The 'newgroup' Control Message ........................ 63
7.1. Digital Signature of Headers .............................. 69 7.2.1.1. The Body of the 'newgroup' Control Message ........ 64
7.2. Group Control Messages .................................... 70 7.2.1.2. Application/news-groupinfo ........................ 64
7.2.1. The 'newgroup' Control Message ........................ 70 7.2.1.3. Initial Articles .................................. 66
7.2.1.1. The Body of the 'newgroup' Control Message ........ 71 7.2.1.4. Example ........................................... 66
7.2.1.2. Application/news-groupinfo ........................ 71 7.2.2. The 'rmgroup' Control Message ......................... 67
7.2.1.3. Initial Articles .................................. 73 7.2.2.1. Example ........................................... 67
7.2.1.4. Example ........................................... 73 7.2.3. The 'mvgroup' Control Message ......................... 68
7.2.2. The 'rmgroup' Control Message ......................... 74 7.2.3.1. Example ........................................... 69
7.2.2.1. Example ........................................... 74 7.2.4. The 'checkgroups' Control Message ..................... 70
7.2.3. The 'mvgroup' Control Message ......................... 75 7.2.4.1. Application/news-checkgroups ...................... 71
7.2.3.1. Example ........................................... 76 7.3. Cancel .................................................... 71
7.2.4. The 'checkgroups' Control Message ..................... 77 7.4. Ihave, sendme ............................................. 72
7.2.4.1. Application/news-checkgroups ...................... 78 7.5. Obsolete control messages. ............................... 74
7.3. Cancel .................................................... 79 8. Duties of Various Agents ...................................... 74
7.4. Ihave, sendme ............................................. 80 8.1. General principles to be followed ......................... 74
7.5. Obsolete control messages. ............................... 81 8.2. Duties of an Injecting Agent .............................. 75
8. Duties of Various Agents ...................................... 81 8.2.1. Proto-articles ........................................ 75
8.1. General principles to be followed ......................... 81 8.2.2. Procedure to be followed by Injecting Agents .......... 75
8.2. Duties of an Injecting Agent .............................. 82 8.3. Duties of a Relaying Agent ................................ 77
8.2.1. Proto-articles ........................................ 82 8.4. Duties of a Serving Agent ................................. 79
8.2.2. Procedure to be followed by Injecting Agents .......... 83 8.5. Duties of a Posting Agent ................................. 79
8.3. Duties of a Relaying Agent ................................ 85 8.6. Duties of a Followup Agent ................................ 80
8.4. Duties of a Serving Agent ................................. 86 8.7. Duties of a Moderator ..................................... 80
8.5. Duties of a Posting Agent ................................. 87 8.8. Duties of a Gateway ....................................... 82
8.6. Duties of a Followup Agent ................................ 87 8.8.1. Duties of an Outgoing Gateway ......................... 83
8.7. Duties of a Moderator ..................................... 88 8.8.2. Duties of an Incoming Gateway ......................... 84
8.8. Duties of a Gateway ....................................... 90 8.8.3. Example ............................................... 86
8.8.1. Duties of an Outgoing Gateway ......................... 91 9. Security and Related Considerations ........................... 86
8.8.1.1. Gatewaying into email ............................. 91 9.1. Leakage ................................................... 87
8.8.2. Duties of an Incoming Gateway ......................... 93 9.2. Attacks ................................................... 87
8.8.3. Example ............................................... 95 9.2.1. Denial of Service ..................................... 87
9. Security and Related Considerations ........................... 96 9.2.2. Compromise of System Integrity ........................ 88
9.1. Leakage ................................................... 96 9.3. Liability ................................................. 89
9.2. Attacks ................................................... 96 10. IANA Considerations .......................................... 90
9.2.1. Denial of Service ..................................... 96 11. References ................................................... 90
9.2.2. Compromise of System Integrity ........................ 97 12. Acknowledgements ............................................. 93
9.3. Liability ................................................. 99 13. Contact Address .............................................. 94
10. IANA Considerations .......................................... 99 Appendix A.1 - A-News Article Format .............................. 94
News Article Format February 2003 News Article Format April 2003
11. References ................................................... 99 Appendix A.2 - Early B-News Article Format ........................ 95
12. Acknowledgements ............................................. 102 Appendix A.3 - Obsolete Headers ................................... 95
13. Contact Address .............................................. 103 Appendix A.4 - Obsolete Control Messages .......................... 96
Appendix A.1 - A-News Article Format .............................. 103 Appendix B - Collected Syntax ..................................... 97
Appendix A.2 - Early B-News Article Format ........................ 104 Appendix B.1 - Characters, Atoms and Folding ...................... 97
Appendix A.3 - Obsolete Headers ................................... 105 Appendix B.2 - Basic Forms ........................................ 98
Appendix A.4 - Obsolete Control Messages .......................... 105 Appendix B.3 - Headers ............................................ 100
Appendix B - Collected Syntax ..................................... 106 Appendix B.3.1 - Header outlines .................................. 100
Appendix B.1 - Characters, Atoms and Folding ...................... 106 Appendix B.3.2 - Control-message outlines ......................... 102
Appendix B.2 - Basic Forms ........................................ 108 Appendix B.3.3 - Other header rules ............................... 102
Appendix B.3 - Headers ............................................ 109 Appendix C - Notices .............................................. 104
Appendix B.3.1 - Header outlines .................................. 109 News Article Format April 2003
Appendix B.3.2 - Control-message outlines ......................... 111
Appendix B.3.3 - Other header rules ............................... 112
Appendix C - Notices .............................................. 114
News Article Format February 2003
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" (which resemble email messages) and for retrieving news "articles" (which resemble email messages) and for
exchanging them amongst a readership which is potentially widely exchanging them amongst a readership which is potentially widely
distributed. It is organized around "newsgroups", with the distributed. It is organized around "newsgroups", with the
expectation that each reader will be able to see all articles posted expectation that each reader will be able to see all articles posted
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tolerant of poorly designed interfaces than mere computers, articles tolerant of poorly designed interfaces than mere computers, articles
in breach of established policy can cause considerable annoyance to in breach of established policy can cause considerable annoyance to
their recipients. their recipients.
Policies may well vary from network to network, from hierarchy to Policies may well vary from network to network, from hierarchy to
hierarchy within one network, and even between individual newsgroups hierarchy within one network, and even between individual newsgroups
within one hierarchy. It is assumed, for the purposes of this within one hierarchy. It is assumed, for the purposes of this
standard, that agencies with varying degrees of authority to standard, that agencies with varying degrees of authority to
establish such policies will exist, and that where they do not, establish such policies will exist, and that where they do not,
policy will be established by mutual agreement. For the benefit of policy will be established by mutual agreement. For the benefit of
News Article Format February 2003 News Article Format April 2003
networks and hierarchies without such established agencies, and to networks and hierarchies without such established agencies, and to
provide a basis upon which all agencies can build, this present provide a basis upon which all agencies can build, this present
standard often provides default policy parameters, usually standard often provides default policy parameters, usually
introducing them by a phrase such as "As a matter of policy ...". introducing them by a phrase such as "As a matter of policy ...".
1.2. Objectives 1.2. Objectives
The purpose of this present standard is to define the format of The purpose of this present standard is to define the format of
articles and the protocols to be used for Netnews in general, and for articles and the protocols to be used for Netnews in general, and for
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1.4. Transport 1.4. Transport
As in this standard's predecessors, the exact means used to transmit As in this standard's predecessors, the exact means used to transmit
articles from one host to another is not specified. NNTP [NNTP] is articles from one host to another is not specified. NNTP [NNTP] is
the most common transmission method on the Internet, but much the most common transmission method on the Internet, but much
transmission takes place entirely independent of the Internet. Other transmission takes place entirely independent of the Internet. Other
methods in use include the UUCP protocol [RFC 976] extensively used methods in use include the UUCP protocol [RFC 976] extensively used
in the early days of Usenet, FTP, downloading via satellite, tape in the early days of Usenet, FTP, downloading via satellite, tape
archives, and physically delivered magnetic and optical media. archives, and physically delivered magnetic and optical media.
News Article Format February 2003 News Article Format April 2003
2. Definitions, Notations and Conventions 2. Definitions, Notations and Conventions
2.1. Definitions 2.1. Definitions
An "article" is the unit of news, analogous to an [RFC 2822] An "article" is the unit of news, analogous to an [RFC 2822]
"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. into the news system.
A "message identifier" (5.3) is a unique identifier for an article, A "message identifier" (5.3) is a unique identifier for an article,
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A "reader" is the person or software reading news articles. A "reader" is the person or software reading news articles.
A "reading agent" is software which presents articles to a reader. A "reading agent" is software which presents articles to a reader.
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 (the followup's "precursor"). an earlier article (the followup's "precursor").
A "followup agent" is a combination of reading agent and posting A "followup agent" is a combination of reading agent and posting
agent that aids in the preparation and posting of a followup. agent that aids in the preparation and posting of a followup.
News Article Format February 2003 News Article Format April 2003
An (email) "address" is the mailbox [RFC 2822] (or more particularly An (email) "address" is the mailbox [RFC 2822] (or more particularly
the addr-spec within that mailbox) which directs the delivery of an the addr-spec within that mailbox) which directs the delivery of an
email to its intended recipient, who is said to "own" that address. email to its intended recipient, who is said to "own" that address.
An article's "reply address" is the address to which mailed replies An article's "reply address" is the address to which mailed replies
should be sent. This is the address specified in the article's From- should be sent. This is the address specified in the article's From-
header (5.2), unless it also has a Reply-To-header (6.1). header (5.2), unless it also has a Reply-To-header (6.1).
A "sender" is the person or software (usually, but not always, the A "sender" is the person or software (usually, but not always, the
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and those using other formats. and those using other formats.
2.2. Textual Notations 2.2. Textual Notations
This standard contains explanatory NOTEs using the following format. This standard contains explanatory NOTEs using the following format.
These may be skipped by persons interested solely in the content of These may be skipped by persons interested solely in the content of
the specification. The purpose of the notes is to explain why choices the specification. The purpose of the notes is to explain why choices
were made, to place them in context, or to suggest possible were made, to place them in context, or to suggest possible
implementation techniques. implementation techniques.
News Article Format February 2003 News Article Format April 2003
NOTE: While such explanatory notes may seem superfluous in NOTE: While such explanatory notes may seem superfluous in
principle, they often help the less-than-omniscient reader grasp principle, they often help the less-than-omniscient reader grasp
the purpose of the specification and the constraints involved. the purpose of the specification and the constraints involved.
Given the limitations of natural language for descriptive Given the limitations of natural language for descriptive
purposes, this improves the probability that implementors and purposes, this improves the probability that implementors and
users will understand the true intent of the specification in users will understand the true intent of the specification in
cases where the wording is not entirely clear. cases where the wording is not entirely clear.
"US-ASCII" is short for "the ANSI X3.4 character set" [ANSI X3.4]. "US-ASCII" is short for "the ANSI X3.4 character set" [ANSI X3.4].
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Wherever the context permits, use of the masculine includes the Wherever the context permits, use of the masculine includes the
feminine and use of the singular includes the plural, and vice versa. feminine and use of the singular includes the plural, and vice versa.
Throughout this standard we will give examples of various Throughout this standard we will give examples of various
definitions, headers and other specifications. It needs to be definitions, headers and other specifications. It needs to be
remembered that these samples are for the aid of the reader only and remembered that these samples are for the aid of the reader only and
do NOT define any specification themselves. In order to prevent do NOT define any specification themselves. In order to prevent
possible conflict with "Real World" entities and people the top level possible conflict with "Real World" entities and people the top level
domain ".example" is used in all sample domains and addresses. The domain ".example" is used in all sample domains and addresses. The
News Article Format February 2003 News Article Format April 2003
hierarchy "example.*" is also used as a sample hierarchy. hierarchy "example.*" is also used as a sample hierarchy.
Information on the ".example" top level domain is in [RFC 2606]. Information on the ".example" top level domain is in [RFC 2606].
2.3. Relation To Email and MIME 2.3. Relation To Email and MIME
The primary intent of this standard is to describe the news article The primary intent of this standard is to describe the news article
format. Insofar as news articles are a subset of the email message format. Insofar as news articles are a subset of the email message
format augmented by some new headers, this standard incorporates many format augmented by some new headers, this standard incorporates many
(though not all) of the provisions of [RFC 2822], with the aim of (though not all) of the provisions of [RFC 2822], with the aim of
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header = other-header header = other-header
header =/ Date-header header =/ Date-header
are equivalent to the single rule are equivalent to the single rule
header = other-header / Date-header header = other-header / Date-header
2.4.2. Syntax adapted from Email and MIME 2.4.2. Syntax adapted from Email and MIME
Much of the syntax of Netnews Articles is based on the corresponding Much of the syntax of Netnews Articles is based on the corresponding
syntax defined in [RFC 2822] or in the MIME specifications [RFC 2045] syntax defined in [RFC 2822] or in the MIME specifications [RFC 2045]
et seq, which are deemed to have been incorporated into this standard et seq, which are deemed to have been incorporated into this standard
as required. However, there are some important differences arising as required. However, there are some differences arising from some
from the fact that [RFC 2822] does not recognize anything beyond US- special requirements of Netnews and the fact that [RFC 2822] includes
ASCII characters, that it does not recognize the MIME headers [RFC much syntax described as "obsolete" (which is excluded from this
2045], and that it includes much syntax described as "obsolete" standard, as detailed below).
(which is excluded from this standard, as detailed below).
NOTE: Netnews parsers historically have been much less NOTE: Netnews parsers historically have been much less
permissive than Email parsers, and this is reflected in the permissive than Email parsers, and this is reflected in the
modifications referred to, and in some further specific rules. modifications referred to, and in some further specific rules.
News Article Format February 2003
The following syntactic rules therefore supersede the corresponding The following syntactic rules therefore supersede the corresponding
rules given in [RFC 2822] and [RFC 2045], thus allowing UTF-8 rules given in [RFC 2822] and [RFC 2045].
characters [RFC 2279] to appear in certain contexts (the five rules
beginning with "strict-" reflect the corresponding original rules
from [RFC 2822]).
UTF8-2 = %xC2-DF UTF8-tail
UTF8-3 = %xE0 %xA0-BF UTF8-tail / %xE1-EC 2(UTF8-tail) /
%xED %x80-9F UTF8-tail / %xEE-EF 2(UTF8-tail)
UTF8-4 = %xF0 %x90-BF 2(UTF8-tail) / %xF1-F7 3(UTF8-tail)
UTF8-5 = %xF8 %x88-BF 3(UTF8-tail) / %xF9-FB 4(UTF8-tail)
UTF8-6 = %xFC %x84-BF 4(UTF8-tail) / %xFD 5(UTF8-tail)
UTF8-tail = %x80-BF
UTF8-xtra-char = UTF8-2 / UTF8-3 / UTF8-4 / UTF8-5 / UTF8-6
text = %d1-9 / ; all UTF-8 characters except
%d11-12 / ; US-ASCII NUL, CR and LF
%d14-127 /
UTF8-xtra-char
ctext = NO-WS-CTL / ; all of <text> except
%d33-39 / ; SP, HTAB, "(", ")"
%d42-91 / ; "\" and DEL
%d93-126 /
UTF8-xtra-char
qtext = NO-WS-CTL / ; all of <text> except
%d33 / ; SP, HTAB, "\" DQUOTE
%d35-91 / ; and DEL
%d93-126 /
UTF8-xtra-char
utext = NO-WS-CTL / ; Non white space controls
%d33-126 / ; The rest of UTF-8
UTF8-xtra-char
strict-text = %d1-9 / ; text restricted to
%d11-12 / ; US-ASCII
%d14-127
strict-qtext = NO-WS-CTL / ; qtext restricted to
%d33 / ; US-ASCII
%d35-91 /
%d93-126
strict-quoted-pair
= "\" strict-text
strict-qcontent = strict-qtext / strict-quoted-pair
strict-quoted-string
= [CFWS] DQUOTE
*( [FWS] strict-qcontent ) [FWS]
DQUOTE [CFWS]
unstructured = 1*( [FWS] utext ) [FWS]
The syntax for UTF8-xtra-char excludes those redundant sequences of News Article Format April 2003
octets which cannot occur in UTF-8, as defined by [RFC 2279], either
because they would not be the shortest possible encodings of some UCS
character [ISO/IEC 10646], or they would represent one of the
characters D800 through DFFF, disallowed in UCS because of their
surrogate use in the UTF-16 encoding. These sequences MUST NOT be
generated by posting agents. Where they occur inadvertently, they
News Article Format February 2003
SHOULD be passed on untouched by other agents, but attempts to unstructured = 1*( [FWS] ( utext / encoded-word ) ) [FWS]
interpret them as malformed UTF-8 MUST NOT be made. However, if there [The one rule might not seem much of a difference, but there are likely
is reason to suppose they are representations of some other character to be others brought into here later as part of this reorganization. So
set they MAY, as suggested in section 4.4.1, be interpreted as such. the existing structure is left alone for now.]
The syntax also includes, for completeness, the cases UTF8-5 and
UTF8-6 which cannot, in fact, arise in [UNICODE 3.2] (though they
might conceivably arise in some future extension).
Observe, in contradistinction to [RFC 2822], that an unstructured Observe, in contradistinction to [RFC 2822], that an unstructured
header MUST contain at least one non-whitespace character (see also header MUST contain at least one non-whitespace character (see also
remarks about empty headers in 4.2.6). remarks about empty headers in 4.2.6).
Wherever in this standard the syntax is stated to be taken from [RFC Wherever in this standard the syntax is stated to be taken from [RFC
2822], it is to be understood as the syntax defined by [RFC 2822] 2822], it is to be understood as the syntax defined by [RFC 2822]
after making the above changes, but NOT including any syntax defined after making the above change(s), but NOT including any syntax
in section 4 ("Obsolete syntax") of [RFC 2822]. Software compliant defined in section 4 ("Obsolete syntax") of [RFC 2822]. Software
with this standard MUST NOT generate any of the syntactic forms compliant with this standard MUST NOT generate any of the syntactic
defined in that Obsolete Syntax, although it MAY accept such forms defined in that Obsolete Syntax, although it MAY accept such
syntactic forms. Certain syntax from the MIME specifications [RFC syntactic forms. Certain syntax from the MIME specifications [RFC
2045] et seq is also considered a part of this standard (see 6.21). 2045] et seq is also considered a part of this standard (see 6.21).
2.4.3. Syntax copied from other standards 2.4.3. Syntax copied from other standards
The following syntactic forms, taken from [RFC 2234] or from [RFC The following syntactic forms, taken from [RFC 2234] or from [RFC
2822], are repeated here for convenience only: 2822] and adapted to incorporate variations introduced in [RFC 2047],
are repeated here for convenience only:
ALPHA = %x41-5A / ; A-Z ALPHA = %x41-5A / ; A-Z
%x61-7A ; a-z %x61-7A ; a-z
CR = %x0D ; carriage return CR = %x0D ; carriage return
CRLF = CR LF CRLF = CR LF
DIGIT = %x30-39 ; 0-9 DIGIT = %x30-39 ; 0-9
HTAB = %x09 ; horizontal tab HTAB = %x09 ; horizontal tab
LF = %x0A ; line feed LF = %x0A ; line feed
SP = %x20 ; space SP = %x20 ; space
NO-WS-CTL = %d1-8 / ; US-ASCII control characters NO-WS-CTL = %d1-8 / ; US-ASCII control characters
skipping to change at page 13, line 54 skipping to change at page 12, line 53
%d127 %d127
specials = "(" / ")" / ; Special characters used in specials = "(" / ")" / ; Special characters used in
"<" / ">" / ; other parts of the syntax "<" / ">" / ; other parts of the syntax
"[" / "]" / "[" / "]" /
":" / ";" / ":" / ";" /
"@" / "\" / "@" / "\" /
"," / "." / "," / "." /
DQUOTE DQUOTE
WSP = SP / HTAB ; whitespace characters WSP = SP / HTAB ; whitespace characters
FWS = ([*WSP CRLF] 1*WSP); folding whitespace FWS = ([*WSP CRLF] 1*WSP); folding whitespace
ccontent = ctext / quoted-pair / comment ccontent = ctext / quoted-pair / comment / encoded-word
comment = "(" *([FWS] ccontent) [FWS] ")" comment = "(" *([FWS] ccontent) [FWS] ")"
CFWS = *([FWS] comment) ( ([FWS] comment) / FWS ) CFWS = *([FWS] comment) ( ([FWS] comment) / FWS )
DQUOTE = %d34 ; quote mark DQUOTE = %d34 ; quote mark
quoted-pair = "\" text quoted-pair = "\" text
News Article Format February 2003 News Article Format April 2003
atext = ALPHA / DIGIT / atext = ALPHA / DIGIT /
"!" / "#" / ; Any US-ASCII character except "!" / "#" / ; Any US-ASCII character except
"$" / "%" / ; controls, SP, and specials. "$" / "%" / ; controls, SP, and specials.
"&" / "'" / ; Used for atoms "&" / "'" / ; Used for atoms
"*" / "+" / "*" / "+" /
"-" / "/" / "-" / "/" /
"=" / "?" / "=" / "?" /
"^" / "_" / "^" / "_" /
"`" / "{" / "`" / "{" /
"|" / "}" / "|" / "}" /
"~" "~"
atom = [CFWS] 1*atext [CFWS] atom = [CFWS] 1*atext [CFWS]
dot-atom = [CFWS] dot-atom-text [CFWS] dot-atom = [CFWS] dot-atom-text [CFWS]
dot-atom-text = 1*atext *( "." 1*atext ) dot-atom-text = 1*atext *( "." 1*atext )
qcontent = qtext / quoted-pair qcontent = qtext / quoted-pair
quoted-string = [CFWS] DQUOTE quoted-string = [CFWS] DQUOTE
*( [FWS] qcontent ) [FWS] *( [FWS] qcontent ) [FWS]
DQUOTE [CFWS] DQUOTE [CFWS]
word = atom / quoted-string word = atom / quoted-string
phrase = 1*word phrase = 1*( [CFWS] encoded-word [CFWS] / word )
The following are taken from [RFC 2045] and [RFC 2231] adapted to use
the folding syntax from [RFC 2822]:
charset = <registered character set name>
; [RFC 2978]
language = <registered language tag>
; [RFC 3066]
encoded-word = "=?" charset ["*" language] "?" encoding
"?" encoded-text "?="
parameter = regular-parameter / extended-parameter
regular-parameter = [CFWS] regular-parameter-name [CFWS]
"=" value
regular-parameter-name = attribute [section]
attribute = 1*attribute-char
attribute-char= <any (US-ASCII) CHAR except SPACE, CTLs,
"*", "'", "%", or tspecials>
tspecials = "(" / ")" / "<" / ">" / "@" /
"," / ";" / ":" / "\" / DQUOTE /
"/" / "[" / "]" / "?" / "="
extended-parameter
= ( [CFWS] extended-initial-name [CFWS]
"=" extended-initial-value ) /
( [CFWS] extended-other-names [CFWS]
"=" extended-other-values )
value = [CFWS] token [CFWS] / quoted-string
token = 1*<any (US-ASCII) CHAR except SP, CTLs,
or tspecials>
NOTE: Following [RFC 2234], literal text included in the syntax NOTE: Following [RFC 2234], literal text included in the syntax
is to be regarded as case-insensitive. However, in is to be regarded as case-insensitive. However, in
contradistinction to [RFC 2822], the Netnews protocols are contradistinction to [RFC 2822], the Netnews protocols are
sensitive to case in some instances (as in newsgroup-names, some sensitive to case in some instances (as in newsgroup-names, some
header parameters, etc.). Care has been taken to indicate this header parameters, etc.). Care has been taken to indicate this
News Article Format April 2003
explicitly where required. explicitly where required.
As in [RFC 2822], where any quoted-pair appears it is to be As in [RFC 2822], where any quoted-pair appears it is to be
interpreted as its text character alone. That is to say, the "\" interpreted as its text character alone. That is to say, the "\"
character that appears as part of a quoted-pair is semantically character that appears as part of a quoted-pair is semantically
"invisible". "invisible".
Again, as in [RFC 2822], strings of characters that include Again, as in [RFC 2822], strings of characters that include
characters not syntactically allowed in some particular context may characters not syntactically allowed in some particular context may
be incorporated into a quoted-string by "encapsulating" them between be incorporated into a quoted-string by "encapsulating" them between
skipping to change at page 14, line 54 skipping to change at page 14, line 28
as to form a quoted-pair, and possibly introducing folding by as to form a quoted-pair, and possibly introducing folding by
prefixing some WSP with CRLF. prefixing some WSP with CRLF.
The semantic value of a quoted-string (i.e. the result of reversing The semantic value of a quoted-string (i.e. the result of reversing
the encapsulation) is a string of characters which includes neither the encapsulation) is a string of characters which includes neither
the optional CFWS outside of the quote characters, nor the quote the optional CFWS outside of the quote characters, nor the quote
characters themselves, nor any CRLF contained within any FWS between characters themselves, nor any CRLF contained within any FWS between
the two quote characters, nor the "\" which introduces any quoted- the two quote characters, nor the "\" which introduces any quoted-
pair. pair.
For the purposes of section 5 of [RFC 2047] all headers (4.1) defined
in this standard are to be considered as "extension message header
fields" (insofar as they are not already so considered under the
existing Email standards), permitting the use of [RFC 2047] encodings
within any unstructured header, or within any comment or phrase
permitted within any structured header. The syntax of encoded-text
and of encoding can be found in [RFC 2047], and there are
restrictions on the characters that may occur within an encoded-text,
depending on its context. These restrictions MUST be observed, as
must the restrictions on the overall length of an encoded-word.
2.5. Language 2.5. Language
Various constant strings in this standard, such as header names and Various constant strings in this standard, such as header names and
month names, are derived from English words. Despite their month names, are derived from English words. Despite their
derivation, these words do NOT change when the poster or reader derivation, these words do NOT change when the poster or reader
employing them is interacting in a language other than English. employing them is interacting in a language other than English.
News Article Format February 2003
Posting and reading agents MAY translate as appropriate in their Posting and reading agents MAY translate as appropriate in their
interaction with the poster or reader, but the forms that actually interaction with the poster or reader, but the forms that actually
appear in articles as transmitted MUST be the English-derived ones appear in articles as transmitted MUST be the English-derived ones
defined in this standard. defined in this standard.
3. Changes to the existing protocols 3. Changes to the existing protocols
This standard prescribes many changes, clarifications and new This standard prescribes many changes, clarifications and new
features since the protocols described in [RFC 1036] and [Son-of- features since the protocols described in [RFC 1036] and [Son-of-
1036]. It is the intention that they can be assimilated into Usenet 1036]. It is the intention that they can be assimilated into Usenet
as it presently operates without major interruption to the service, as it presently operates without major interruption to the service,
though some of the new features may not begin to show benefit until though some of the new features may not begin to show benefit until
they become widely implemented. This section summarizes the main they become widely implemented. This section summarizes the main
changes, and comments on some features of the transition. changes, and comments on some features of the transition.
News Article Format April 2003
3.1. Principal Changes 3.1. Principal Changes
o The [RFC 2822] conventions for parenthesis-enclosed comments in o The [RFC 2822] conventions for parenthesis-enclosed comments in
headers are supported. headers are supported.
o Whitespace is permitted in Newsgroups-headers, permitting folding o Whitespace is permitted in Newsgroups-headers, permitting folding
of such headers. Indeed, all headers can now be folded. of such headers. Indeed, all headers can now be folded.
o An enhanced syntax for the Path-header enables the injection o An enhanced syntax for the Path-header 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
certainty. certainty.
o Netnews is firmly established as an 8bit medium and all headers
are deemed to be in the UTF-8 character set (thus permitting, in
particular, the use of non-ASCII newsgroup-names).
o Large parts of MIME are recognized as an integral part of o Large parts of MIME are recognized as an integral part of
Netnews. Netnews.
o There is a new Control message 'mvgroup' to facilitate moving a o There is a new Control message 'mvgroup' to facilitate moving a
group to a different place (name) in a hierarchy. group to a different place (name) in a hierarchy.
o There are several new headers defined, notably Archive, o There are several new headers defined, notably Archive,
Complaints-To, Injector-Info, Mail-Copies-To, Posted-And-Mailed Complaints-To, Injector-Info, Mail-Copies-To, Posted-And-Mailed
and User-Agent, leading to increased functionality. and User-Agent, leading to increased functionality.
o Provision has been made for almost all headers to have MIME-style o Provision has been made for almost all headers to have MIME-style
parameters (to be ignored if not recognized), thus facilitating parameters (to be ignored if not recognized), thus facilitating
extension of those headers in future standards. extension of those headers in future standards.
skipping to change at page 16, line 4 skipping to change at page 15, line 43
3.2. Transitional Arrangements 3.2. Transitional Arrangements
An important distinction must be made between serving and relaying An important distinction must be made between serving and relaying
agents, which are responsible for the distribution and storage of agents, which are responsible for the distribution and storage of
news articles, and user agents, which are responsible for news articles, and user agents, which are responsible for
interactions with users. It is important that the former should be interactions with users. It is important that the former should be
upgraded to conform to this standard as soon as possible to provide upgraded to conform to this standard as soon as possible to provide
the benefit of the enhanced facilities. Fortunately, the number of the benefit of the enhanced facilities. Fortunately, the number of
distinct implementations of such agents is rather small, at least so distinct implementations of such agents is rather small, at least so
far as the main "backbone" of Usenet is concerned, and many of the far as the main "backbone" of Usenet is concerned, and many of the
News Article Format February 2003
new features are already supported. Contrariwise, there are a great new features are already supported. Contrariwise, there are a great
number of implementations of user agents, installed on a vastly number of implementations of user agents, installed on a vastly
greater number of small sites. Therefore, the new functionality has greater number of small sites. Therefore, the new functionality has
been designed so that existing agents may continue to be used, been designed so that existing agents may continue to be used,
although the full benefits may not be realised until a substantial although the full benefits may not be realised until a substantial
proportion of them have been upgraded. proportion of them have been upgraded.
In the list which follows, care has been taken to distinguish the In the list which follows, care has been taken to distinguish the
implications for both kinds of agent. implications for both kinds of agent.
o [RFC 2822] style comments in headers do not affect serving and o [RFC 2822] style comments in headers do not affect serving and
relaying agents (note that the Message-ID-, Newsgroups-, relaying agents (note that the Message-ID-, Newsgroups-,
Distribution- and Path-headers do not contain them). They are Distribution- and Path-headers do not contain them). They are
unlikely to hinder their proper display in existing reading unlikely to hinder their proper display in existing reading
agents except in the case of the References-header in agents agents except in the case of the References-header in agents
which thread articles. Therefore, it is provided that they SHOULD which thread articles. Therefore, it is provided that they SHOULD
NOT be generated except where permitted by the previous NOT be generated except where permitted by the previous
standards. standards.
News Article Format April 2003
o Because of its importance to all serving agents, the extension o Because of its importance to all serving agents, the extension
permitting whitespace and folding in Newsgroups-headers SHOULD permitting whitespace and folding in Newsgroups-headers SHOULD
NOT be used until it has been widely deployed amongst relaying NOT be used until it has been widely deployed amongst relaying
agents. User agents are unaffected. agents. User agents are unaffected.
o The new style of Path-header is already consistent with the o The new style of Path-header is already consistent with the
previous standards. However, the intention is that relaying previous standards. However, the intention is that relaying
agents should eventually reject articles in the old style, and so agents should eventually reject articles in the old style, and so
this possibility should be offered as a configurable option in this possibility should be offered as a configurable option in
relaying agents. User agents are unaffected. relaying agents. User agents are unaffected.
o The vast majority of serving, relaying and transport agents are
believed to be already 8bit clean (in the slightly restricted
sense in which that term is used in the MIME standards). User
agents that do not implement MIME may be disadvantaged, but no
more so than at present when faced with 8bit characters (which
currently abound in spite of the previous standards).
o The introduction of MIME reflects a practice that is already o The introduction of MIME reflects a practice that is already
widespread. Articles in strict compliance with the previous widespread. Articles in strict compliance with the previous
standards (using strict US-ASCII) will be unaffected. Many user standards (using strict US-ASCII) will be unaffected. Many user
agents already support it, at least to the extent of widely used agents already support it, at least to the extent of widely used
charsets such as ISO-8859-1. Users expecting to read articles charsets such as ISO-8859-1. Users expecting to read articles
using other charsets will need to acquire suitable reading using other charsets will need to acquire suitable reading
agents. It is not intended, in general, that any single user agents. It is not intended, in general, that any single user
agent will be able to display every charset known to IANA, but agent will be able to display every charset known to IANA, but
all such agents MUST support US-ASCII. Serving and relaying all such agents MUST support US-ASCII. Serving and relaying
agents are not affected. agents are not affected.
o The use of the UTF-8 charset for headers will not affect any
existing usage that complies with the previous standards, since
US-ASCII is a strict subset of UTF-8. Insofar as newsgroup-names
containing non-ASCII characters can now be expected to arise,
some support from serving and relaying agents will be desirable,
although it has been established that most current serving agents
can already cope with such names without modification (although
perhaps not in an ideal manner). Note that it is not necessary
for serving and relaying agents to understand all the characters
available in UTF-8, though it is desirable for them to be
displayable for diagnostic purposes via some escape mechanism
News Article Format February 2003
using, for example, the visible subset of US-ASCII.
o Users expecting to read headers containing non-ASCII characters
expressed in UTF-8 will need to acquire suitable reading agents
(it is not anticipated that current reading agents will fail to
display such articles, but those non-ASCII characters will likely
appear in some illegible form). The same will be true for users
reading such headers in email on the far side of a news-to-email
gateway; in that case, it will be necessary for the gateway to be
upgraded (see 8.8.1.1).
o The new Control: mvgroup command will need to be implemented in o The new Control: mvgroup command will need to be implemented in
serving agents. For the benefit of older serving agents it is serving agents. For the benefit of older serving agents it is
therefore RECOMMENDED that it be followed shortly by a therefore RECOMMENDED that it be followed shortly by a
corresponding newgroup command and it MUST always be followed by corresponding newgroup command and it MUST always be followed by
a rmgroup command for the old group after a reasonable overlap a rmgroup command for the old group after a reasonable overlap
period. An implementation of the mvgroup command as an alias for period. An implementation of the mvgroup command as an alias for
the newgroup command would thus be minimally conforming. User the newgroup command would thus be minimally conforming. User
agents are unaffected. agents are unaffected.
o All the headers newly introduced by this standard can safely be o All the headers newly introduced by this standard can safely be
ignored by existing software, albeit with loss of the new ignored by existing software, albeit with loss of the new
skipping to change at page 17, line 49 skipping to change at page 17, line 5
other standard> other standard>
separator = CRLF separator = CRLF
body = *( *998text CRLF ) body = *( *998text CRLF )
However, the rule given above for header is incomplete. Further However, the rule given above for header is incomplete. Further
alternatives will be added incrementally as the various Netnews alternatives will be added incrementally as the various Netnews
headers are introduced in this standard (or in future extensions), headers are introduced in this standard (or in future extensions),
using the "=/" notation defined in [RFC 2234]. For example, a using the "=/" notation defined in [RFC 2234]. For example, a
typical USENET-header would be defined as follows: typical USENET-header would be defined as follows:
News Article Format April 2003
header =/ USENET-header header =/ USENET-header
USENET-header = "USENET" ":" SP USENET-content USENET-header = "USENET" ":" SP USENET-content
*( ";" ( USENET-parameter / *( ";" ( USENET-parameter /
extension-parameter ) ) extension-parameter ) )
USENET-content = <syntax specific to that USENET-header> USENET-content = <syntax specific to that USENET-header>
USENET-parameter = <a parameter specific to that USENET-header> USENET-parameter = <a parameter specific to that USENET-header>
where the USENET-parameter, which MUST always be of the same where the USENET-parameter, which MUST always be of the same
syntactic form as an extension-parameter (see below), is not provided syntactic form as an extension-parameter (see below), is not provided
in all headers, and even the extension-parameter is omitted in some in all headers, and even the extension-parameter is omitted in some
cases cases (see 4.2.2). Observe that "USENET" is (and MUST be) of cases (see 4.2.2). Observe that "USENET" is (and MUST be) of the
News Article Format February 2003 syntactic form of a header-name.
the syntactic form of a header-name.
extension-parameter= <a parameter not defined by this standard> extension-parameter= <a parameter not defined by this standard>
parameter = attribute "=" value x-attribute = "x-" attribute
attribute = [CFWS] token [CFWS]
x-token = "x-" token
token = 1*<any (US-ASCII) CHAR except SP, CTLs,
or tspecials>
tspecials = "(" / ")" / "<" / ">" / "@" /
"," / ";" / ":" / "\" / DQUOTE /
"/" / "[" / "]" / "?" / "="
value = [CFWS] token [CFWS] / quoted-string
An article consists of some headers followed by a body. An empty line An article consists of some headers followed by a body. An empty line
separates the two. The headers contain structured information about separates the two. The headers contain structured information about
the article and its transmission. A header begins with a header-name the article and its transmission. A header begins with a header-name
identifying it, and can be continued onto subsequent lines as identifying it, and can be continued onto subsequent lines as
described in section 4.2.3. The body is largely unstructured text described in section 4.2.3. The body is largely unstructured text
significant only to the poster and the readers. significant only to the poster and the readers.
NOTE: Terminology here follows the current custom in the news NOTE: Terminology here follows the current custom in the news
community, rather than the [RFC 2822] convention of referring to community, rather than the [RFC 2822] convention of referring to
skipping to change at page 18, line 53 skipping to change at page 17, line 57
The order of headers in an article is not significant. However, The order of headers in an article is not significant. However,
posting agents are encouraged to put mandatory headers (section 5) posting agents are encouraged to put mandatory headers (section 5)
first, followed by optional headers (section 6), followed by first, followed by optional headers (section 6), followed by
experimental headers and headers not defined in this standard or its experimental headers and headers not defined in this standard or its
extensions. Relaying agents MUST NOT change the order of the headers extensions. Relaying agents MUST NOT change the order of the headers
in an article. in an article.
4.2.1. Naming of Headers 4.2.1. Naming of Headers
Despite the restrictions on header-name syntax imposed by the Despite the restrictions on header-name syntax imposed by the
grammar, relaying and reading agents SHOULD tolerate header-names grammar, relaying, serving and reading agents SHOULD tolerate
containing any US-ASCII printable character other than colon (":", header-names containing any US-ASCII printable character other than
US-ASCII 58). colon (":", US-ASCII 58).
News Article Format April 2003
Whilst relaying agents MUST accept, and pass on unaltered, any non- Whilst relaying agents MUST accept, and pass on unaltered, any non-
variant header whose header-name is syntactically correct, and variant header whose header-name is syntactically correct, and
reading agents MUST enable them to be displayed, at least optionally, reading agents MUST enable them to be displayed, at least optionally,
News Article Format February 2003
posting and injecting agents SHOULD NOT generate headers other than posting and injecting agents SHOULD NOT generate headers other than
o headers established by this standard or any extension to it; o headers established by this standard or any extension to it;
o those recognized by other IETF-established standards, notably the o those recognized by other IETF-established standards, notably the
Email standard [RFC 2822] and its extensions, excluding any Email standard [RFC 2822] and its extensions, excluding any
explicitly deprecated for Netnews (e.g. see section 9.2.1 for the explicitly deprecated for Netnews (e.g. see section 9.2.1 for the
deprecated Disposition-Notification-To-header); or, deprecated Disposition-Notification-To-header); or,
alternatively, those listed in some future IANA registry of alternatively, those listed in some future IANA registry of
recognized headers; recognized headers;
o experimental headers beginning with "X-" (as defined in 4.2.5.1); o experimental headers beginning with "X-" (as defined in 4.2.5.1);
o on a provisional basis only, headers related to new protocols o on a provisional basis only, headers related to new protocols
under development which are the subject of (or intended to be the under development which are the subject of (or intended to be the
subject of) some IETF-approved RFC (whether Informational, subject of) some IETF-approved RFC (whether Informational,
Experimental or Standards-Track). Experimental or Standards-Track).
However, software SHOULD NOT attempt to interpret headers not However, software SHOULD NOT attempt to interpret headers not
specifically intended to be meaningful in the Netnews environment. specifically intended to be meaningful in the Netnews environment.
[However, if [KLYNE], which defines an IANA registry of recognized
headers, becomes accepted before we are done (which is likely), then
that paragraph can be simplified very considerably.]
Header-names are case-insensitive. There is a preferred case Header-names are case-insensitive. There is a preferred case
convention, which posters and posting agents Ought to use: each convention, which posters and posting agents Ought to use: each
hyphen-separated "word" has its initial letter (if any) in uppercase hyphen-separated "word" has its initial letter (if any) in uppercase
and the rest in lowercase, except that some abbreviations have all and the rest in lowercase, except that some abbreviations have all
letters uppercase (e.g. "Message-ID" and "MIME-Version"). The forms letters uppercase (e.g. "Message-ID" and "MIME-Version"). The forms
given in the various rules defining headers in this standard are the given in the various rules defining headers in this standard are the
preferred forms for them. Relaying and reading agents MUST, however, preferred forms for them. Relaying and reading agents MUST, however,
tolerate articles not obeying this convention. tolerate articles not obeying this convention.
4.2.2. MIME-style Parameters 4.2.2. MIME-style Parameters
A few header-specific MIME-style parameters are defined in this A few header-specific MIME-style parameters are defined in this
standard, but there is also provision for generic extension- standard, but there is also provision for generic extension-
parameters to appear in most headers for the purpose of allowing parameters to appear in most headers for the purpose of allowing
future extensions to those headers. Observe that such parameters do future extensions to those headers. Observe that such parameters do
not, in general, occur in headers defined in other standards, except not, in general, occur in headers defined in other standards, except
for the MIME standards [RFC 2045] et seq. and their extensions. for the MIME standards [RFC 2045] et seq. and their extensions.
Extension-parameters, other than those using x-tokens, MUST NOT be Extension-parameters, other than those using x-attributes, MUST NOT
used unless they have first been defined in an IETF-approved RFC be used unless they have first been defined in an IETF-approved RFC
(whether Informational, Experimental or Standards-Track) or, on a (whether Informational, Experimental or Standards-Track) or, on a
provisional basis only, in relation to new protocols under provisional basis only, in relation to new protocols under
development which are the subject of (or intended to be the subject development which are the subject of (or intended to be the subject
of) some such IETF-approved RFC. They MUST ONLY be defined for use in of) some such IETF-approved RFC. They MUST ONLY be defined for use in
those headers where the syntax of this standard so allows. They those headers where the syntax of this standard so allows. They
SHOULD NOT, at present, be defined for use in headers in widespread SHOULD NOT, at present, be defined for use in headers in widespread
use prior to the introduction of this standard (this restriction is use prior to the introduction of this standard (this restriction is
likely to be removed in a future version of this standard). likely to be removed in a future version of this standard).
Nevertheless, compliant software MUST accept such parameters wherever Nevertheless, compliant software MUST accept such parameters wherever
syntactically allowed in this standard (ignoring them if their syntactically allowed in this standard (ignoring them if their
meaning is unknown) and SHOULD accept (and ignore) them in all meaning is unknown) and SHOULD accept (and ignore) them in all
structured headers wherever defined. structured headers wherever defined.
News Article Format April 2003
[We could go further, and establish an IANA registry for these [We could go further, and establish an IANA registry for these
parameters, preloaded with the ones already defined in this standard. A parameters, preloaded with the ones already defined in this standard. A
good model for setting up such a registry is to be found in RFC 2183 good model for setting up such a registry is to be found in RFC 2183
(Content-Disposition).] (Content-Disposition).]
News Article Format February 2003
NOTE: The syntax does not permit extension-parameters in NOTE: The syntax does not permit extension-parameters in
unstructured headers (where they are unnecessary) or in certain unstructured headers (where they are unnecessary) or in certain
headers (notably the Date-, From-, Message-ID-, Reply-To-, headers (notably the Date-, From-, Message-ID-, Reply-To-,
Sender-, Keywords-, Mail-Copies-To-, References-, Supersedes- Sender-, Keywords-, Mail-Copies-To-, References-, Supersedes-
and Complaints-To-headers) which are the same (or similar to) and Complaints-To-headers) which are the same (or similar to)
headers already existing in the Email standards. headers already existing in the Email standards.
Each header-specific MIME-style parameter introduced in this standard Each header-specific MIME-style parameter introduced in this standard
is described by specifying is described by specifying
(a) the token to be used in its attribute, and (a) its attribute, and
(b) the syntax rule(s) defining the object(s) permitted in its (b) the syntax rule(s) defining the object(s) permitted in its
value. value.
If a value object is not of the syntactic form of a token, it MUST Any parameter, or set of parameters with numbered sections, which,
(and otherwise MAY) be encapsulated in a quoted-string (see 2.4.3). according to [RFC 2231], is semantically equivalent to an unnumbered
Observe that the syntax of a parameter also allows additional WSP, regular-parameter with that attribute and value may be used.
folding and comments.
The semantics of a parameter is always to associate the token in its NOTE: If the value is not of the syntactic form of a token and
attribute with the object represented by the token, or the semantic is not encoded as an extended-value, it is necessary to
value (2.4.3) of the quoted-string, contained in its value. encapsulate it within a quoted-string (see 2.4.3). Observe that
the syntax of a parameter also allows additional WSP, folding
and comments.
The semantics of a parameter is always to associate its attribute
with the object represented by the token, or the semantic value
(2.4.3) of the quoted-string, contained in its value.
For example, the posting-sender-parameter (6.19) is defined to be For example, the posting-sender-parameter (6.19) is defined to be
<a parameter with attribute "sender" and value some sender-value> <a parameter with attribute "sender" and value some sender-value>
where where
sender-value = mailbox / "verified" sender-value = mailbox / "verified"
A valid posting-sender-parameter would be A valid posting-sender-parameter would be
sender = "\"Joe D. Bloggs\" <jdbloggs@bloggs.example>" (authinfo) sender = "\"Joe D. Bloggs\" <jdbloggs@bloggs.example>" (authinfo)
The comment (syntactically part of the quoted-string) is irrelevant. The comment (syntactically part of the quoted-string) is irrelevant.
The actual mailbox (to be used, for example, if email is to be sent The actual mailbox (to be used, for example, if email is to be sent
to the sender) is to the sender) is
skipping to change at page 20, line 50 skipping to change at page 20, line 4
Each header is logically a single line of characters comprising the Each header is logically a single line of characters comprising the
header-name, the colon with its following SP, the content, and any header-name, the colon with its following SP, the content, and any
parameters. For convenience, however, the content and parameters can parameters. For convenience, however, the content and parameters can
be "folded" into a multiple line representation by inserting a CRLF be "folded" into a multiple line representation by inserting a CRLF
before any WSP contained within any FWS or CFWS (but not any other SP before any WSP contained within any FWS or CFWS (but not any other SP
or HTAB) allowed by this standard. For example, the header: or HTAB) allowed by this standard. For example, the header:
Approved: modname@modsite.example (Moderator of example.foo.bar) Approved: modname@modsite.example (Moderator of example.foo.bar)
can be represented as: can be represented as:
Approved: modname@modsite.example Approved: modname@modsite.example
(Moderator of example.foo.bar) (Moderator of example.foo.bar)
News Article Format April 2003
FWS occurs at many places in the syntax (usually within a CFWS) in FWS occurs at many places in the syntax (usually within a CFWS) in
order to allow the inclusion of comments, whitespace and folding. The order to allow the inclusion of comments, whitespace and folding. The
syntax is in fact ambiguous insofar as it sometimes allows two syntax is in fact ambiguous insofar as it sometimes allows two
consecutive instantiations of FWS (as least one of which is always consecutive instantiations of FWS (as least one of which is always
optional), or of an optional FWS followed by an explicit CRLF. optional), or of an optional FWS followed by an explicit CRLF.
However, all such cases MUST be treated as if the optional However, all such cases MUST be treated as if the optional
instantiation (or one of them) had not been allowed. It is thus instantiation (or one of them) had not been allowed. It is thus
precluded that any line of a header should be made up of whitespace precluded that any line of a header should be made up of whitespace
characters and nothing else (for such a line might otherwise have characters and nothing else (for such a line might otherwise have
News Article Format February 2003
been interpreted by a non-compliant agent as the separator between been interpreted by a non-compliant agent as the separator between
the headers and the body of the article). the headers and the body of the article).
NOTE: This does not lead to semantic ambiguity because, unless NOTE: This does not lead to semantic ambiguity because, unless
specifically stated otherwise, the presence or absence of specifically stated otherwise, the presence or absence of
folding, a comment or additional WSP has no semantic meaning folding, a comment or additional WSP has no semantic meaning
and, in particular, it is a matter of indifference whether it and, in particular, it is a matter of indifference whether it
forms a part of the syntactic construct preceding it or the one forms a part of the syntactic construct preceding it or the one
following it. following it.
skipping to change at page 21, line 52 skipping to change at page 21, line 5
Posters and posting agents SHOULD use SP, not HTAB, where white space Posters and posting agents SHOULD use SP, not HTAB, where white space
is desired in headers (some existing software expects this). Relaying is desired in headers (some existing software expects this). Relaying
and serving agents SHOULD accept HTAB in all such cases, however. and serving agents SHOULD accept HTAB in all such cases, however.
4.2.4. Comments 4.2.4. Comments
Strings of characters which are treated as comments may be included Strings of characters which are treated as comments may be included
in headers wherever the syntactic element CFWS occurs. They consist in headers wherever the syntactic element CFWS occurs. They consist
of characters enclosed in parentheses. Comments may be nested. of characters enclosed in parentheses. Comments may be nested.
News Article Format April 2003
NOTE: Although CFWS occurs wherever whitespace is allowed in NOTE: Although CFWS occurs wherever whitespace is allowed in
almost all headers, there are exceptions where only FWS is almost all headers, there are exceptions where only FWS is
permitted (hence folding but no comments). Notably, this happens permitted (hence folding but no comments). Notably, this happens
in the case of the Message-ID-, Newsgroups-, Distribution-, in the case of the Message-ID-, Newsgroups-, Distribution-,
Path- and Followup-To-headers, and within the Date-header except Path- and Followup-To-headers, and within the Date-header except
right at the end. right at the end.
News Article Format February 2003
A comment is normally used to provide some human readable A comment is normally used to provide some human readable
informational text, except at the end of a mailbox which contains no informational text, except at the end of a mailbox which contains no
phrase, as in phrase, as in
fred@foo.bar.example (Fred Bloggs) fred@foo.bar.example (Fred Bloggs)
as opposed to as opposed to
"Fred Bloggs" <fred@foo.bar.example> . "Fred Bloggs" <fred@foo.bar.example> .
The former is a deprecated, but commonly encountered, usage and The former is a deprecated, but commonly encountered, usage and
reading agents SHOULD take special note of such comments as reading agents SHOULD take special note of such comments as
indicating the name of the person whose mailbox it is. In all other indicating the name of the person whose mailbox it is. In all other
skipping to change at page 22, line 54 skipping to change at page 22, line 5
They are to be used for experimental Netnews features, or for They are to be used for experimental Netnews features, or for
enabling additional material to be propagated with an article. They enabling additional material to be propagated with an article. They
are not (and will not be) defined by this, or any, standard. are not (and will not be) defined by this, or any, standard.
NOTE: Experimental headers are suitable for situations where NOTE: Experimental headers are suitable for situations where
they need only to be human readable. They are not intended to be they need only to be human readable. They are not intended to be
recognized by widely deployed Netnews software and, should such recognized by widely deployed Netnews software and, should such
a requirement be envisaged, it is preferable to use a normal a requirement be envisaged, it is preferable to use a normal
header on the provisional basis set out in section 4.2.1. header on the provisional basis set out in section 4.2.1.
News Article Format April 2003
4.2.5.2. Inheritable Headers 4.2.5.2. Inheritable Headers
Subject only to the overriding ability of the poster to determine the Subject only to the overriding ability of the poster to determine the
contents of the headers in a proto-article, headers with the contents of the headers in a proto-article, headers with the
inheritable property MUST be copied by followup agents (perhaps with inheritable property MUST be copied by followup agents (perhaps with
some modification) into the followup article, and headers without some modification) into the followup article, and headers without
that property MUST NOT be so copied. Examples include: that property MUST NOT be so copied. Examples include:
News Article Format February 2003
o Newsgroups (5.5) - copied from the precursor, subject to any o Newsgroups (5.5) - copied from the precursor, subject to any
Followup-To-header. Followup-To-header.
o Subject (5.4) - modified by prefixing with "Re: ", but otherwise o Subject (5.4) - modified by prefixing with "Re: ", but otherwise
copied from the precursor. copied from the precursor.
o References (6.10) - copied from the precursor, with the addition o References (6.10) - copied from the precursor, with the addition
of the precursor's Message-ID. of the precursor's Message-ID.
o Distribution (6.6) - copied from the precursor. o Distribution (6.6) - copied from the precursor.
NOTE: The Keywords-header is not inheritable, though some older NOTE: The Keywords-header is not inheritable, though some older
newsreaders treated it as such. newsreaders treated it as such.
skipping to change at page 23, line 53 skipping to change at page 23, line 5
delete empty headers from articles before posting them; relaying delete empty headers from articles before posting them; relaying
agents MUST pass them untouched. agents MUST pass them untouched.
Headers that merely state defaults explicitly (e.g., a Followup-To- Headers that merely state defaults explicitly (e.g., a Followup-To-
header with the same content as the Newsgroups-header, or a MIME header with the same content as the Newsgroups-header, or a MIME
Content-Type-header with contents "text/plain; charset=us-ascii") or Content-Type-header with contents "text/plain; charset=us-ascii") or
state information that reading agents can typically determine easily state information that reading agents can typically determine easily
themselves (e.g. the length of the body in octets) are redundant and themselves (e.g. the length of the body in octets) are redundant and
posters and posting agents Ought Not to include them. posters and posting agents Ought Not to include them.
News Article Format April 2003
4.3. Body 4.3. Body
4.3.1. Body Format Issues 4.3.1. Body Format Issues
The body of an article SHOULD NOT be empty. A posting or injecting The body of an article SHOULD NOT be empty. A posting or injecting
agent which does not reject such an article entirely SHOULD at least agent which does not reject such an article entirely SHOULD at least
issue a warning message to the poster and supply a non-empty body. issue a warning message to the poster and supply a non-empty body.
Note that the separator line MUST be present even if the body is Note that the separator line MUST be present even if the body is
News Article Format February 2003
empty. empty.
NOTE: Some existing news software is known to react badly to NOTE: Some existing news software is known to react badly to
body-less articles, hence the request for posting and injecting body-less articles, hence the request for posting and injecting
agents to insert a body in such cases. The sentence "This agents to insert a body in such cases. The sentence "This
article was probably generated by a buggy news reader" has article was probably generated by a buggy news reader" has
traditionally been used in this situation. traditionally been used in this situation.
Note that an article body is a sequence of lines terminated by CRLFs, Note that an article body is a sequence of lines terminated by CRLFs,
not arbitrary binary data, and in particular it MUST end with a CRLF. not arbitrary binary data, and in particular it MUST end with a CRLF.
skipping to change at page 24, line 52 skipping to change at page 24, line 5
relied on for essential meaning. relied on for essential meaning.
4.3.2. Body Conventions 4.3.2. Body Conventions
A body is by default an uninterpreted sequence of octets for most of A body is by default an uninterpreted sequence of octets for most of
the purposes of this standard. However, a MIME Content-Type-header the purposes of this standard. However, a MIME Content-Type-header
may impose some structure or intended interpretation upon it, and may may impose some structure or intended interpretation upon it, and may
also specify the character set in accordance with which the octets also specify the character set in accordance with which the octets
are to be interpreted. are to be interpreted.
News Article Format April 2003
The following conventions for quotations, attributions and The following conventions for quotations, attributions and
signatures, although not mandated by this standard, describe widely signatures, although not mandated by this standard, describe widely
used practices. They are documented here in order to establish their used practices. They are documented here in order to establish their
correct usage, and the use of the words "MUST", "SHOULD", etc. is to correct usage, and the use of the words "MUST", "SHOULD", etc. is to
be understood in that context. be understood in that context.
News Article Format February 2003
It is conventional for followup agents to enable the incorporation of It is conventional for followup agents to enable the incorporation of
the followed-up article (the "precursor") as a quotation. This SHOULD the followed-up article (the "precursor") as a quotation. This SHOULD
be done by prefacing each line of the quoted text (even if it is be done by prefacing each line of the quoted text (even if it is
empty) with the character ">" (or perhaps with "> " in the case of a empty) with the character ">" (or perhaps with "> " in the case of a
previously unquoted line). This will result in multiple levels of ">" previously unquoted line). This will result in multiple levels of ">"
when quoted content itself contains quoted content, and it will also when quoted content itself contains quoted content, and it will also
facilitate the automatic analysis of articles. facilitate the automatic analysis of articles.
NOTE: Posters should edit quoted context to trim it down to the NOTE: Posters should edit quoted context to trim it down to the
minimum necessary. However, followup agents Ought Not to attempt minimum necessary. However, followup agents Ought Not to attempt
skipping to change at page 25, line 55 skipping to change at page 25, line 5
<...> <...>
o The various fields may be separated by arbitrary text and they o The various fields may be separated by arbitrary text and they
may be folded in the same way as headers, but attributions SHOULD may be folded in the same way as headers, but attributions SHOULD
always be terminated by a ":" followed by CRLF. always be terminated by a ":" followed by CRLF.
Further examples: Further examples:
On comp.foo in <1234@bar.example> on 24 Dec 2001 16:40:20 +0000, On comp.foo in <1234@bar.example> on 24 Dec 2001 16:40:20 +0000,
Joe D. Bloggs <jdbloggs@bar.example> wrote: Joe D. Bloggs <jdbloggs@bar.example> wrote:
News Article Format April 2003
Am 24. Dez 2001 schrieb Helmut Schmidt <helmut@bar.example>: Am 24. Dez 2001 schrieb Helmut Schmidt <helmut@bar.example>:
A "personal signature" is a short closing text automatically added to A "personal signature" is a short closing text automatically added to
the end of articles by posting agents, identifying the poster and the end of articles by posting agents, identifying the poster and
giving his network addresses, etc. Whenever a poster or posting agent giving his network addresses, etc. Whenever a poster or posting agent
appends such a signature to an article, it MUST be preceded with a appends such a signature to an article, it MUST be preceded with a
News Article Format February 2003
delimiter line containing (only) two hyphens (US-ASCII 45) followed delimiter line containing (only) two hyphens (US-ASCII 45) followed
by one SP (US-ASCII 32). The signature is considered to extend from by one SP (US-ASCII 32). The signature is considered to extend from
the last occurrence of that delimiter up to the end of the article the last occurrence of that delimiter up to the end of the article
(or up to the end of the part in the case of a multipart MIME body). (or up to the end of the part in the case of a multipart MIME body).
Followup agents, when incorporating quoted text from a precursor, Followup agents, when incorporating quoted text from a precursor,
Ought Not to include the signature in the quotation. Posting agents Ought Not to include the signature in the quotation. Posting agents
Ought to discourage (at least with a warning) signatures of excessive Ought to discourage (at least with a warning) signatures of excessive
length (4 lines is a commonly accepted limit). length (4 lines is a commonly accepted limit).
4.4. Characters and Character Sets 4.4. Characters and Character Sets
skipping to change at page 26, line 27 skipping to change at page 25, line 34
Transmission paths for news articles MUST treat news articles as Transmission paths for news articles MUST treat news articles as
uninterpreted sequences of octets, excluding the values 0 (US-ASCII uninterpreted sequences of octets, excluding the values 0 (US-ASCII
NUL) and 13 and 10 (US-ASCII CR and LF, which MUST ONLY appear in the NUL) and 13 and 10 (US-ASCII CR and LF, which MUST ONLY appear in the
combination CRLF which denotes a line separator). combination CRLF which denotes a line separator).
NOTE: this corresponds to the range of octets permitted for MIME NOTE: this corresponds to the range of octets permitted for MIME
"8bit data" [RFC 2045]. Thus raw binary data cannot be "8bit data" [RFC 2045]. Thus raw binary data cannot be
transmitted in an article body except by the use of a Content- transmitted in an article body except by the use of a Content-
Transfer-Encoding such as base64. Transfer-Encoding such as base64.
[Tentative paragraph to deal with IMAP] In particular, transmission paths MUST convey all headers (including
body part headers and headers within message/rfc822 objects) intact,
This requirement includes the transmissiom paths between posting even if they contain octets representing non-ASCII charsets. These
agents, injecting agents, relaying agents, serving agents and reading requirements include the transmissiom paths between posting agents,
agents, but it does NOT include paths traversed by Netnews articles injecting agents, relaying agents, serving agents and reading agents,
that have been converted to Email (8.8.1.1). It SHOULD extend to but NOT the paths traversed by Netnews articles that have been
IMAP4 servers which provide access to Netnews (see the extension gatewayed into Email (8.8.1).
described in section 4.4.3). [At some point it will be necessary for the IMAP standards to catch up
with these requirements.]
Character data is represented by octets in accordance with some Character data is represented by octets in accordance with some
encoding scheme (UTF-8 for headers, and determined by the Content- encoding scheme (US-ASCII for headers, and determined by the
Type- and Content-Transfer-Encoding-headers for bodies). Content-Type- and Content-Transfer-Encoding-headers for bodies).
If it comes to a relaying agent's attention that it is being asked to If it comes to a relaying agent's attention that it is being asked to
pass an article using the Content-Transfer-Encoding "8bit" to a pass an article using the Content-Transfer-Encoding "8bit" to a
relaying agent that does not support it, it SHOULD report this error relaying agent that does not support it, it SHOULD report this error
to its administrator. It MUST refuse to pass the article and MUST NOT to its administrator. It MUST refuse to pass the article and MUST NOT
re-encode it with different MIME encodings. re-encode it with different MIME encodings.
NOTE: This strategy will do little harm. The target relaying NOTE: This strategy will do little harm. The target relaying
agent is unlikely to be able to make use of the article on its agent is unlikely to be able to make use of the article on its
own servers, and the usual flooding algorithm will likely find own servers, and the usual flooding algorithm will likely find
some alternative route to get the article to destinations where some alternative route to get the article to destinations where
it is needed. it is needed.
4.4.1. Character Sets within Article Headers News Article Format April 2003
Within article headers, characters are represented as octets
according to the UTF-8 encoding scheme [RFC 2279] or [ISO/IEC 10646],
and hence all the characters in Unicode [UNICODE 3.2] or in the
Universal Multiple-Octet Coded Character Set (UCS) [ISO/IEC 10646]
(which is essentially identical to Unicode and expected to remain so)
are potentially available. Although it will usually be unnecessary
News Article Format February 2003
to use language tagging within headers, the tagging facilities
provided in [UNICODE 3.2] (code points U+E0000 through U+E007F) MAY
be used for that purpose.
NOTE: UTF-8 is an encoding for the [ISO/IEC 10646] character set
(in both its 16 and 32 bit forms) with the property that any
octet less than 128 immediately represents the corresponding
US-ASCII character, thus ensuring upwards compatibility with
previous practice. Non-ASCII characters from Unicode are
represented by sequences of octets satisfying the syntax of a
UTF8-xtra-char (2.4.2), which excludes certain octet sequences
not explicitly permitted by [RFC 2279]. Unicode includes all
characters from the ISO-8859 series of characters sets [ISO
8859] (which includes all Cyrillic, Greek and Arabic characters)
together with the more elaborate characters used in Asian
countries. See the NOTEs in the following section for the
appropriate treatment of Unicode characters by reading agents.
[The sentence mentioning [RFC 2279] could be simplified if [RFC 2279bis]
has been accepted by the time this standard is published.]
Notwithstanding the great flexibility permitted by UTF-8, there is
need for restraint in its use in order that the essential components
of headers may be discerned using reading agents that cannot present
the full Unicode range. In particular, header-names and tokens MUST
be in US-ASCII, and certain other components of headers, as defined
elsewhere in this standard - notably msg-ids, date-times, dot-atoms,
domains and path-identities - MUST be in US-ASCII. Comments, phrases
(as in mailboxes) and unstructured headers (such as the Subject-,
Organization- and Summary-headers) MAY use the full range of UTF-8
characters, but SHOULD nevertheless be invariant under Unicode
normalization NFC [UNICODE 3.2].
NOTE: Unicode allows for composite characters made up of a
starter character - which can be a letter, number, punctuation
mark, or symbol - plus zero or more combining marks (such as
accents, diacritics, and similar). The requirement that a
composite be invariant under normalization NFC means that, where
it could be written in more than one way, only one particular
one of those ways is allowed (for example, the single character
E-acute is preferred over E followed by a non-spacing acute
accent, and A-ring is preferred over the Angstrom symbol). At
least for the main European languages, for which all the needed
composites are already available as single characters, it is
unlikely that posting agents will need to take any special steps
to ensure normalization.
In the particular case of newsgroup-names (see 5.5) there are more
stringent requirements regarding the normalization and other usages
of Unicode.
Where the use of non-ASCII characters is permitted as above, they MAY
be encoded in UTF-8 or they MAY be encoded using the MIME mechanisms
defined in [RFC 2047] and [RFC 2231]. For this purpose, all headers
defined in this standard are to be considered as "extension message
News Article Format February 2003
header fields" for the purpose of section 5 of [RFC 2047] (insofar as 4.4.1. Character Sets within Article Headers
they are not already covered under the existing Email standards). The
effect of this is to permit the use of [RFC 2047] encodings within
any unstructured header, or within any comment or phrase permitted
within any structured header. Additionally, [RFC 2047] is
considered to incorporate the extension to allow language tags within
encoded-words described in [RFC 2231]. Likewise, the syntax for
parameter (see 4.1 above) is to be considered as replaced by the
revised syntax given in [RFC 2231], the effect of which is to allow
the use of parameter value continuations, character sets and language
information within the MIME-style parameters introduced in this
standard (4.2.2).
[We could go further and include that syntax explicitly in this
document.]
Exceptionally, where some other protocol, for example the Where the use of non-ASCII characters is required, they MUST be
authentication protocol based on OpenPGP defined in [RFC 3156], encoded using the MIME mechanisms defined in [RFC 2047] and [RFC
restricts some header to 7-bit data, the [RFC 2047] and [RFC 2231] 2231].
encodings MUST be used in preference to UTF-8 (see also the similar
restriction in 6.21.3).
[This presupposes that the extension to permit UTF-8 in body part
headers in 6.21.1 survives.]
Examples: Examples:
Organization: Technische =?iso-8859-1?Q?Universit=E4t_M=FCnchen?= Organization: Technische =?iso-8859-1?Q?Universit=E4t_M=FCnchen?=
Approved: =?iso-8859-1?Q?Fran=E7ois_Faur=E9?= <ff@modsite.example> Approved: =?iso-8859-1?Q?Fran=E7ois_Faur=E9?= <ff@modsite.example>
(=?iso-8859-1?Q*fr?Mod=E9rateur_autoris=E9?=) (=?iso-8859-1?Q*fr?Mod=E9rateur_autoris=E9?=)
Archive: yes; filename*=iso-8859-1'es'ma=F1ana.txt Archive: yes; filename*=iso-8859-1'es'ma=F1ana.txt
Reading agents MUST support the use of UTF-8, [RFC 2047] and [RFC NOTE: The raw use of non-ASCII character sets or of encodings
2231] in all those headers defined in this standard and in the Email other than those described above is not compliant with this
standards, at least to the extent of their ability to display the standard, even though such usage has been seen in some
characters presented to them. Moreover, since Netnews articles are hierarchies (with no indication of which character set has been
regularly emailed as well as posted, and the current Email standards used beyond the user's ability to guess based upon other clues
do not currently admit the use of full UTF-8 in headers, posting in the article, or custom within the newsgroup). Future
agents MUST ensure that [RFC 2047] and [RFC 2231] are used in extensions to this standard may make provision for other
preference to UTF-8 in those cases, at least within the emailed character sets, hence the requirement that octets beyond the
version (see also 6.9 and 8.8.1.1). US-ASCII range be transported without error.
Encoding by other means is not compliant with this standard.
Nevertheless, encoding using other character sets (with no indication
of which one beyond the user's ability to guess based upon other
clues in the article, or custom within the newsgroup) has been in use
in some hierarchies, and such usage may be expected to continue for
some period after the introduction of this standard. Reading agents
MAY, when such usage is detected, attempt to interpet the header
according to whatever other character set can be deduced, or has been
configued as a default by the reader.
NOTE: It is possible to determine, with a high degree of
accuracy, when a given text containing octets with the 8th bit
set was not encoded using UTF-8, and using this test to recover
such non-compliant texts is therefore commended where no other
harm could arise.
News Article Format February 2003
The [RFC 2047] encoding is not available within headers which contain
a newsgroup-name, notably Newsgroups-headers and Followup-To-headers,
because a newsgroup-name is neither a phrase nor a comment. Moreover
such headers MUST in any case use UTF-8 in order to ensure that
newsgroup-names appear in their canonical form. A special encoding
for newsgroup-names is provided in section 5.5.2 for use when mailing
to moderators and other gatewaying applications (8.7 and 8.8.1.1).
NOTE: The choice between UTF-8 and [RFC 2047] when posting
depends on various factors. Some reading agents do not recogize
[RFC 2047], and some are incapable of decoding UTF-8 (though
there in an increasing tendency for modern reading agents to
understand, or to be configurable to understand, both). Since
headers encoded in UTF-8 are currently prohibited in Email,
special consideration needs to be given to articles that are
both posted and mailed (6.9) or which are mailed to moderators
(see 8.2.2). Posters and implementors of posting agents need to
take account of all these factors when deciding which method to
use.
4.4.2. Character Sets within Article Bodies 4.4.2. Character Sets within Article Bodies
Within article bodies, characters are represented as octets according Within article bodies, characters are represented as octets according
to the encoding scheme implied by any Content-Transfer-Encoding- and to the encoding scheme implied by any Content-Transfer-Encoding- and
Content-Type-headers [RFC 2045]. In the absence of such headers, Content-Type-headers [RFC 2045]. In the absence of such headers,
reading agents cannot be relied upon to display correctly more than reading agents cannot be relied upon to display correctly more than
the US-ASCII characters, though they MUST display at least those. the US-ASCII characters, though they MUST display at least those.
NOTE: The use of non-ASCII characters in the absence of an NOTE: The use of non-ASCII characters in the absence of an
appropriate Content-Type-header is not compliant with this appropriate Content-Type-header is not compliant with this
standard. Nevertheless such usage has been seen in some standard, even though such usage has been seen in some
hierarchies, and it would be reasonable for reading agents to hierarchies (with no indication of which character set has been
make an informed "guess" when confronted with that situation, used beyond the user's ability to guess based upon other clues
and in particular it would be wise at least to test whether they in the article, or custom within the newsgroup).
were in the form of valid UTF-8 (see also the suggestion for
such a test in 4.4.1).
NOTE: It is not expected that reading agents will necessarily be NOTE: It is not expected that reading agents will necessarily be
able to present characters in all possible character sets. For able to present characters in all possible character sets. For
example, a reading agent might be able to present only the ISO- example, a reading agent might be able to present only the ISO-
8859-1 (Latin 1) characters [ISO 8859], in which case it Ought 8859-1 (Latin 1) characters [ISO 8859], in which case it Ought
to present undisplayable characters using some distinctive to present undisplayable characters using some distinctive
glyph, or by exhibiting a suitable warning. glyph, or by exhibiting a suitable warning.
Followup agents MUST be careful to apply appropriate encodings to the Followup agents MUST be careful to apply appropriate encodings to the
outbound followup. A followup to an article containing non-ASCII outbound followup. A followup to an article containing non-ASCII
material is very likely to contain non-ASCII material itself. material is very likely to contain non-ASCII material itself.
4.4.3. The NEWS-8BIT-HEADERS IMAP Extension
[This section is highly tentative, and serves as a placeholder to
indicate that an IMAP extension will be needed in order to ensure
consistency with the present form of this draft. It shows the minimum
extension that seems to be necessary, and would require significant
News Article Format February 2003
further work for any final version.]
The current IMAP4 protocol [RFC 2060] forbids 8-bit characters in
headers (so as to conform with the previous Netnews standard [RFC
1036] amd with the current Email standards).
[That reference to RFC 2060 should be changed to refer to [RFC 2060bis]
if that has been accepted by the time this standard is published.]
Implementations of IMAP4 conforming to this extension MUST
1. In the case of Netnews messages only, accept 8-bit octets in
headers (part specifiers HEADER or MIME, or the header portion of
a MESSAGE/RFC822 part) and pass them on to the client unchanged in
any FETCH response;
2. Interpret all octets in such headers as being in the UTF-8
charset;
3. Include the capability NEWS-8BIT-HEADERS in any CAPABILITY
response.
NOTE: It is the responsibility of the client to interpret such
headers. Users who require to see them displayed correctly will
need to acquire clients with the necessary UTF-8 facilities.
The new capability NEWS-8BIT-HEADERS is to be registered with IANA.
[Memo: remember to update the IANA Considerations section.]
4.5. Size Limits 4.5. Size Limits
Posting agents SHOULD endeavour to keep all header lines, so far as Posting agents SHOULD endeavour to keep all header lines, so far as
is possible, within 79 characters by folding them at suitable places is possible, within 79 characters by folding them at suitable places
(see 4.2.3). However, posting agents MUST permit the poster to (see 4.2.3). However, posting agents MUST permit the poster to
include longer headers if he so insists, and compliant software MUST include longer headers if he so insists, and compliant software MUST
News Article Format April 2003
support headers of at least 998 octets. Likewise, injecting agents support headers of at least 998 octets. Likewise, injecting agents
SHOULD fold any headers generated automatically by themselves. SHOULD fold any headers generated automatically by themselves.
Relaying agents MUST NOT fold headers (i.e. they must pass on the Relaying agents MUST NOT fold headers (i.e. they must pass on the
folding as received). folding as received).
NOTE: There is NO restriction on the number of lines into which NOTE: There is NO restriction on the number of lines into which
a header may be split, and hence there is NO restriction on the a header may be split, and hence there is NO restriction on the
total length of a header (in particular it may, by suitable total length of a header (in particular it may, by suitable
folding, be made to exceed the 998 octets restriction pertaining folding, be made to exceed the 998 octets restriction pertaining
to a single header line). to a single header line).
The syntax provides for the lines of a body to be up to 998 octets in The syntax provides for the lines of a body to be up to 998 octets in
length, not including the CRLF. All software compliant with this length, not including the CRLF. All software compliant with this
standard MUST support lines of at least that length, both in headers standard MUST support lines of at least that length, both in headers
and in bodies, and all such software SHOULD support lines of and in bodies, and all such software SHOULD support lines of
arbitrary length. In particular, relaying agents MUST transmit lines arbitrary length. In particular, relaying agents MUST transmit lines
of arbitrary length without truncation or any other modification. of arbitrary length without truncation or any other modification.
News Article Format February 2003
NOTE: The limit of 998 octets is consistent with the NOTE: The limit of 998 octets is consistent with the
corresponding limit in [RFC 2822]. corresponding limit in [RFC 2822].
In plain-text messages (those with no MIME headers, or those with a In plain-text messages (those with no MIME headers, or those with a
MIME Content-Type of text/plain) posting agents Ought to endeavour to MIME Content-Type of text/plain) posting agents Ought to endeavour to
keep the length of body lines within some reasonable limit. The size keep the length of body lines within some reasonable limit. The size
of this limit is a matter of policy, the default being to keep within of this limit is a matter of policy, the default being to keep within
79 characters at most, and preferably within 72 characters (to allow 79 characters at most, and preferably within 72 characters (to allow
room for quoting in followups). Exceptionally, posting agents Ought room for quoting in followups). Exceptionally, posting agents Ought
Not to adjust the length of quoted lines in followups unless they are Not to adjust the length of quoted lines in followups unless they are
skipping to change at page 31, line 43 skipping to change at page 28, line 4
in kilobytes. in kilobytes.
4.6. Example 4.6. Example
Here is a sample article: Here is a sample article:
Path: server.example/unknown.site2.example@site2.example/ Path: server.example/unknown.site2.example@site2.example/
relay.site.example/site.example/injector.site.example%jsmith relay.site.example/site.example/injector.site.example%jsmith
Newsgroups: example.announce,example.chat Newsgroups: example.announce,example.chat
Message-ID: <9urrt98y53@site1.example> Message-ID: <9urrt98y53@site1.example>
News Article Format April 2003
From: Ann Example <a.example@site1.example> From: Ann Example <a.example@site1.example>
Subject: Announcing a new sample article. Subject: Announcing a new sample article.
Date: Wed, 27 Mar 2002 12:12:50 +0300 Date: Wed, 27 Mar 2002 12:12:50 +0300
Approved: example.announce moderator <jsmith@site.example> Approved: example.announce moderator <jsmith@site.example>
Followup-To: example.chat Followup-To: example.chat
Reply-To: Ann Example <a.example+replies@site1.example> Reply-To: Ann Example <a.example+replies@site1.example>
Expires: Mon, 22 Apr 2002 12:12:50 +0300 Expires: Mon, 22 Apr 2002 12:12:50 +0300
Organization: Site1, The Number one site for examples. Organization: Site1, The Number one site for examples.
User-Agent: ExampleNews/3.14 (Unix) User-Agent: ExampleNews/3.14 (Unix)
Keywords: example, announcement, standards, RFC 1036, Usefor Keywords: example, announcement, standards, RFC 1036, Usefor
Summary: The URL for the next standard. Summary: The URL for the next standard.
Injector-Info: injector.site.example; posting-host=du003.site.example Injector-Info: injector.site.example; posting-host=du003.site.example
Complaints-To: abuse@site.example Complaints-To: abuse@site.example
Just a quick announcement that a new standard example article has Just a quick announcement that a new standard example article has
been released; it is in the new USEFOR standard obtainable from been released; it is in the new USEFOR standard obtainable from
ftp.ietf.org. ftp.ietf.org.
News Article Format February 2003
Ann. Ann.
-- --
Ann Example <a.example@site1.example> Sample Poster to the Stars Ann Example <a.example@site1.example> Sample Poster to the Stars
"The opinions in this article are bloody good ones" - J. Clarke. "The opinions in this article are bloody good ones" - J. Clarke.
[The RFC Editor is invited to change the above Date and Expires headers [The RFC Editor is invited to change the above Date and Expires headers
to match the actual publication dates and to insert its correct URL.] to match the actual publication dates and to insert its correct URL.]
5. Mandatory Headers 5. Mandatory Headers
skipping to change at page 32, line 43 skipping to change at page 29, line 4
in [RFC 2822], subject to the following revised definition of zone. in [RFC 2822], subject to the following revised definition of zone.
header =/ Date-header header =/ Date-header
Date-header = "Date" ":" SP Date-content Date-header = "Date" ":" SP Date-content
Date-content = date-time Date-content = date-time
zone = (( "+" / "-" ) 4DIGIT) / "UT" / "GMT" zone = (( "+" / "-" ) 4DIGIT) / "UT" / "GMT"
The forms "UT" and "GMT" (indicating universal time) are to be The forms "UT" and "GMT" (indicating universal time) are to be
regarded as obsolete synonyms for "+0000". They MUST be accepted, and regarded as obsolete synonyms for "+0000". They MUST be accepted, and
passed on unchanged, by all agents, but they MUST NOT be generated as passed on unchanged, by all agents, but they MUST NOT be generated as
News Article Format April 2003
part of new articles by posting and injecting agents. The date-time part of new articles by posting and injecting agents. The date-time
MUST be semantically valid as required by [RFC 2822]. Although MUST be semantically valid as required by [RFC 2822]. Although
folding white space is permitted throughout the date-time syntax, it folding white space is permitted throughout the date-time syntax, it
is RECOMMENDED that a single space be used in each place that FWS is RECOMMENDED that a single space be used in each place that FWS
appears (whether it is required or optional). appears (whether it is required or optional).
NOTE: A convention that is sometimes followed is to add a NOTE: A convention that is sometimes followed is to add a
comment, after the date-time, containing the time zone in comment, after the date-time, containing the time zone in
human-readable form, but many of the abbreviations commonly used human-readable form, but many of the abbreviations commonly used
for this purpose are ambiguous. The value given by the <zone> is for this purpose are ambiguous. The value given by the <zone> is
the only definitive form. the only definitive form.
In order to prevent the reinjection of expired articles into the news In order to prevent the reinjection of expired articles into the news
stream, relaying and serving agents MUST refuse "stale" articles stream, relaying and serving agents MUST refuse "stale" articles
whose Date-header predates the earliest articles of which they whose Date-header predates the earliest articles of which they
normally keep record, or which is more than 24 hours into the future normally keep record, or which is more than 24 hours into the future
(though they MAY use a margin less than that 24 hours). Relaying (though they MAY use a margin less than that 24 hours). Relaying
agents MUST NOT modify the Date-header in transit. agents MUST NOT modify the Date-header in transit.
News Article Format February 2003
5.1.1. Examples 5.1.1. Examples
Date: Sat, 26 May 2001 11:13:00 -0500 (EST) Date: Sat, 26 May 2001 11:13:00 -0500 (EST)
Date: 26 May 2001 16:13 +0000 Date: 26 May 2001 16:13 +0000
Date: 26 May 2001 16:13 GMT (Obsolete) Date: 26 May 2001 16:13 GMT (Obsolete)
5.2. From 5.2. From
The From-header contains the email address(es), possibly including The From-header contains the email address(es), possibly including
the full name(s), of the article's poster(s). The content syntax the full name(s), of the article's poster(s). The content syntax
makes use of syntax defined in [RFC 2822], subject to the following makes use of syntax defined in [RFC 2822].
revised definition of local-part.
header =/ From-header header =/ From-header
From-header = "From" ":" SP From-content From-header = "From" ":" SP From-content
From-content = mailbox-list From-content = mailbox-list
addr-spec = local-part "@" domain
local-part = dot-atom / strict-quoted-string
NOTE: This syntax ensures that the local-part of an addr-spec is
restricted to pure US-ASCII (and is thus in strict compliance
with [RFC 2822]), whilst allowing any UTF-8 character to be used
in a preceding quoted-string containing the poster's full name.
If some future extension to the Email protocols should relax
this restriction, one would expect the Netnews protocols to
follow.
Observe that there is no provision for parameters in this Observe that there is no provision for parameters in this
header, or in other headers containing addresses likely to be header, or in other headers containing addresses likely to be
used for sending email (see 4.2.2). used for sending email (see 4.2.2).
Each mailbox in the From-content SHOULD be a valid address, belonging Each mailbox in the From-content SHOULD be a valid address, belonging
to the poster(s) of the article, or person or agent on whose behalf to the poster(s) of the article, or person or agent on whose behalf
the post is being sent (see the Sender-header, 6.2). When, for the post is being sent (see the Sender-header, 6.2). When, for
whatever reason, the poster does not wish to include such an address, whatever reason, the poster does not wish to include such an address,
the From-content SHOULD then be an address which ends in the top the From-content SHOULD then be an address which ends in the top
skipping to change at page 33, line 54 skipping to change at page 30, line 5
NOTE: Since such addresses ending in ".invalid" are NOTE: Since such addresses ending in ".invalid" are
undeliverable, user agents Ought to warn any user attempting to undeliverable, user agents Ought to warn any user attempting to
reply to them and Ought Not, in any case, to attempt to deliver reply to them and Ought Not, in any case, to attempt to deliver
to them (since that would be pointless anyway). Whether or not to them (since that would be pointless anyway). Whether or not
a valid address can subsequently be extracted from such an a valid address can subsequently be extracted from such an
address falls outside the scope of this standard (obviously, address falls outside the scope of this standard (obviously,
posters wishing to disguise their address need to do more than posters wishing to disguise their address need to do more than
just add ".invalid" to it). just add ".invalid" to it).
News Article Format April 2003
Be warned, however, that some injecting agents which are unable Be warned, however, that some injecting agents which are unable
to detect that the address belongs to the poster may choose to to detect that the address belongs to the poster may choose to
insert a Sender-header (but see 8.2.2) or some entry in an insert a Sender-header (but see 8.2.2) or some entry in an
Injector-Info-header (6.19) which discloses some valid address Injector-Info-header (6.19) which discloses some valid address
for the poster. for the poster.
News Article Format February 2003
5.2.1. Examples: 5.2.1. Examples:
From: John Smith <jsmith@site.example> From: John Smith <jsmith@site.example>
From: "John Smith" <jsmith@site.example>, dave@isp.example From: "John Smith" <jsmith@site.example>, dave@isp.example
From: "John D. Smith" <jsmith@site.example>, andrew@isp.example, From: "John D. Smith" <jsmith@site.example>, andrew@isp.example,
fred@site2.example fred@site2.example
From: Jan Jones <jan@please_setup_your_system_correctly.invalid> From: Jan Jones <jan@please_setup_your_system_correctly.invalid>
From: Jan Jones <joe@guess-where.invalid> From: Jan Jones <joe@guess-where.invalid>
From: dave@isp.example (Dave Smith) From: dave@isp.example (Dave Smith)
NOTE: the last example shows a now deprecated convention of NOTE: the last example shows a now deprecated convention of
putting a poster's full name in a comment following the mailbox, putting a poster's full name in a comment following the mailbox,
rather than in a phrase at the start of it. Observe also the use rather than in a phrase at the start of it. Observe also the use
of the quoted-string "John D. Smith" which is required on of the quoted-string "John D. Smith" which is required on
account of presence of the '.' character, and which would also account of presence of the '.' character.
have been required had any UTF8-xtra-char been present.
5.3. Message-ID 5.3. Message-ID
The Message-ID-header contains the article's message identifier, a The Message-ID-header contains the article's message identifier, a
unique identifier distinguishing the article from every other unique identifier distinguishing the article from every other
article. The content syntax makes use of syntax defined in [RFC article. The content syntax makes use of syntax defined in [RFC
2822], subject to the following revised definitions of msg-id, no- 2822], subject to the following revised definitions of msg-id, no-
fold-quote and no-fold-literal. fold-quote and no-fold-literal.
header =/ Message-ID-header header =/ Message-ID-header
Message-ID-header = "Message-ID" ":" SP Message-ID-content Message-ID-header = "Message-ID" ":" SP Message-ID-content
Message-ID-content = [FWS] msg-id [FWS] Message-ID-content = [FWS] msg-id [FWS]
msg-id = "<" id-left "@" id-right ">" msg-id = "<" id-left "@" id-right ">"
id-left = dot-atom-text / no-fold-quote id-left = dot-atom-text / no-fold-quote
id-right = dot-atom-text / no-fold-literal id-right = dot-atom-text / no-fold-literal
no-fold-quote = DQUOTE no-fold-quote = DQUOTE
*( strict-qtext / "\\" / "\" DQUOTE ) *( qtext / "\\" / "\" DQUOTE )
qspecial qspecial
*( strict-qtext / "\\" / "\" DQUOTE ) *( qtext / "\\" / "\" DQUOTE )
DQUOTE DQUOTE
qspecial = "(" / ")" / ; same as specials except qspecial = "(" / ")" / ; same as specials except
"<" / ">" / ; "\" and DQUOTE quoted "<" / ">" / ; "\" and DQUOTE quoted
"[" / "]" / "[" / "]" /
":" / ";" / ":" / ";" /
"@" / "\\" / "@" / "\\" /
"," / "." / "," / "." /
"\" DQUOTE "\" DQUOTE
no-fold-literal = "[" *( dtext / "\[" / "\]" / "\\" ) "]" no-fold-literal = "[" *( dtext / "\[" / "\]" / "\\" ) "]"
[I think we need to ensure that '<' and '>' are excluded from id-left
and id-right.]
News Article Format April 2003
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: Observe that, in contrast to the corresponding header in NOTE: Observe that, in contrast to the corresponding header in
[RFC 2822], the syntax does not allow comments within the [RFC 2822], the syntax does not allow comments within the
Message-ID-header; this is to simplify processing by relaying Message-ID-header; this is to simplify processing by relaying
and serving agents and to ensure interoperability with existing and serving agents and to ensure interoperability with existing
implementations. implementations.
News Article Format February 2003 Msg-ids as defined here are a "normalized" subset of those
defined by [RFC 2822], ensuring that no string of characters is
The restriction to strict-qtext ensures that no UTF8-xtra-char quoted unless strictly necessary (it must contain at least one
can appear. Msg-ids as defined here are a "normalized" subset of qspecial) and no single character is prefixed by a "\" in the
those defined by [RFC 2822], ensuring that no string of form of a quoted-pair unless strictly necessary, and moreover
characters is quoted unless strictly necessary (it must contain there is no possibility for WSP to occur, whether quoted or not.
at least one qspecial) and no single character is prefixed by a The length restriction ensures that systems which accept message
"\" in the form of a quoted-pair unless strictly necessary, and identifiers as a parameter when retrieving an article (e.g.
moreover there is no possibility for WSP to occur, whether [NNTP]) can rely on a bounded length. Observe that msg-id
quoted or not. The length restriction ensures that systems which includes the '<' and '>'.
accept message identifiers as a parameter when retrieving an
article (e.g. [NNTP]) can rely on a bounded length. Observe that
msg-id includes the '<' and '>'.
An agent generating an article's message identifier MUST ensure that An agent generating an article's message identifier MUST ensure that
it is unique (as also required in [RFC 2822]) and that it is chosen it is unique (as also required in [RFC 2822]) and that it is chosen
in such a way that it will NEVER be applied to any other Netnews in such a way that it will NEVER be applied to any other Netnews
article or Email message. However, an article emailed (without article or Email message. However, an article emailed (without
encapsulation) to a moderator (8.2.2 and 8.7) or gatewayed into some encapsulation) to a moderator (8.2.2 and 8.7) or gatewayed into some
other medium (8.8.1) SHOULD retain the same message identifier other medium (8.8.1) SHOULD retain the same message identifier
throughout its travels so long as it remains recognizably the same throughout its travels so long as it remains recognizably the same
article. article.
skipping to change at page 35, line 54 skipping to change at page 32, line 5
5.4. Subject 5.4. Subject
The Subject-header contains a short string identifying the topic of The Subject-header contains a short string identifying the topic of
the message. This is an inheritable header (4.2.5.2) to be copied the message. This is an inheritable header (4.2.5.2) to be copied
into the Subject-header of any followup, in which case the new into the Subject-header of any followup, in which case the new
Subject-content SHOULD then default to the string "Re: " (a "back Subject-content SHOULD then default to the string "Re: " (a "back
reference") followed by the contents of the pure-subject of the reference") followed by the contents of the pure-subject of the
precursor. Any leading "Re: " in that pure-subject MUST be stripped. precursor. Any leading "Re: " in that pure-subject MUST be stripped.
News Article Format April 2003
header =/ Subject-header header =/ Subject-header
Subject-header = "Subject" ":" SP Subject-content Subject-header = "Subject" ":" SP Subject-content
Subject-content = [ [FWS] back-reference ] pure-subject Subject-content = [ [FWS] back-reference ] pure-subject
pure-subject = unstructured pure-subject = unstructured
back-reference = %x52.65.3A.20 back-reference = %x52.65.3A.20
; which is a case-sensitive "Re: " ; which is a case-sensitive "Re: "
News Article Format February 2003
The pure-subject MUST NOT begin with "Re: ". The pure-subject MUST NOT begin with "Re: ".
NOTE: The syntax of unstructured differs from that prescribed in NOTE: The syntax of unstructured differs from that prescribed in
[RFC 2822], so ensuring that the Subject-content is not [RFC 2822], so ensuring that the Subject-content is not
permitted to be completely empty, or to consist of WSP only (see permitted to be completely empty, or to consist of WSP only (see
remarks in 4.2.6 concerning undesirable headers). remarks in 4.2.6 concerning undesirable headers).
Followup agents MAY remove strings that are known to be used Followup agents MAY remove strings that are known to be used
erroneously as back-reference (such as "Re(2): ", "Re:", "RE: ", or erroneously as back-reference (such as "Re(2): ", "Re:", "RE: ", or
skipping to change at page 36, line 51 skipping to change at page 33, line 4
by this standard. "was: " is a convention used by many English- by this standard. "was: " is a convention used by many English-
speaking posters to signal a change in subject matter. Software can speaking posters to signal a change in subject matter. Software can
always recognize such changes from the References-header. always recognize such changes from the References-header.
Subject: Film at 11 Subject: Film at 11
Subject: Re: Film at 11 Subject: Re: Film at 11
Subject: Godwin's law considered harmful (was: Film at 11) Subject: Godwin's law considered harmful (was: Film at 11)
Subject: Godwin's law (was: Film at 11) Subject: Godwin's law (was: Film at 11)
Subject: Re: Godwin's law (was: Film at 11) Subject: Re: Godwin's law (was: Film at 11)
Subject: Re: Godwin's law Subject: Re: Godwin's law
News Article Format April 2003
5.5. Newsgroups 5.5. Newsgroups
The Newsgroups-header's content specifies the newsgroup(s) in which The Newsgroups-header's content specifies the newsgroup(s) in which
the article is intended to appear. It is an inheritable header the article is intended to appear. It is an inheritable header
(4.2.5.2) which then becomes the default Newsgroups-header of any (4.2.5.2) which then becomes the default Newsgroups-header of any
followup, unless a Followup-To-header is present to prescribe followup, unless a Followup-To-header is present to prescribe
otherwise. Articles MUST NOT be passed between relaying agents or to otherwise. Articles MUST NOT be passed between relaying agents or to
serving agents unless the sending agent has been configured to supply serving agents unless the sending agent has been configured to supply
News Article Format February 2003
and the receiving agent to receive at least one of the newsgroup- and the receiving agent to receive at least one of the newsgroup-
names in the Newsgroups-header. names in the Newsgroups-header.
In order to allow newsgroup-names containing Non-ASCII characters,
this section relies heavily on the provisions of the Unicode
Standard. All references to "Unicode" mean [UNICODE 3.2] or any
standard that supersedes it. That document contains guarantees of
strict future upwards compatibility (e.g. no character will be
removed or change classification). Implementors should be aware that
currently unassigned code points (Unicode category Cn) may become
valid characters in future versions of Unicode. Since the poster of
an article might have access to a newer version of that standard,
relaying and serving agents MUST accept such characters, but posting
agents (and indeed all agents) MUST NOT generate them (though they
might well follow up to newsgroup-names containing them).
header =/ Newsgroups-header header =/ Newsgroups-header
Newsgroups-header = "Newsgroups" ":" SP Newsgroups-content Newsgroups-header = "Newsgroups" ":" SP Newsgroups-content
*( ";" extension-parameter ) *( ";" extension-parameter )
Newsgroups-content = [FWS] newsgroup-name Newsgroups-content = [FWS] newsgroup-name
*( [FWS] ng-delim [FWS] newsgroup-name ) *( [FWS] ng-delim [FWS] newsgroup-name )
[FWS] [FWS]
newsgroup-name = component *( "." component ) newsgroup-name = component *( "." component )
component = 1*component-grapheme component = 1*component-grapheme
ng-delim = "," ng-delim = ","
component-grapheme = combiner-base *combiner-mark component-grapheme = DIGIT / ALPHA / "+" / "-" / "_"
combiner-base = combiner-ASCII / combiner-extended
combiner-ASCII = DIGIT / ALPHA / "+" / "-" / "_"
combiner-extended = <any character with a Unicode code value
of 0080 or greater but excluding any
character in Unicode categories
Cc, Cf, Cs, M* and Z*>
combiner-mark = <any character with a Unicode code value of
0080 or greater and in Unicode category M*>
NOTE: the excluded characters in a combiner-extended are control
characters (Cc), format control characters (Cf), surrogates
(Cs), marks (M*) and separators (Z*). In particular, this
excludes all whitespace characters. To all intents and
purposes, a component-grapheme is what a user might regard as a
single "character" as displayed on his screen, though it might
be transmitted as several actual characters (e.g. q-circumflex
is two characters). Note also that, in some writing schemes,
several component-graphemes will merge into one visible object
of variable size.
Each component MUST be invariant under Unicode normalization NFKC
(cf. the weaker normalization requirement for other headers in
section 4.4.1 which specified no more than normalization NFC, and see
also the explanatory NOTE in that section).
NOTE: As a result of of this restriction, a name has only one
valid form. Implementations can assume that a straight (case
sensitive) comparison of characters or octets is sufficient to
News Article Format February 2003
compare two newsgroup-names.
The requirement that names be invariant under NFKC, rather than
NFC, means that all characters with a "compatibility
decomposition" are forbidden (Unicode provides the property
"NFKC_NO" to make this test easier). The effect is to exclude
variant forms of characters, such as superscripts and
subscripts, wide and narrow forms, font variants, encircled
forms, ligatures, and so on, as their use could cause confusion.
There is insufficient experience in this area to determine
whether this is the right long-term solution. Implementors
should therefore be aware that a future version of this standard
might reduce the requirement in the direction of NFC as opposed
to NFKC.
NOTE: An implementation is not required to apply NFKC, or any
other normalization, to newsgroup-names. Only agencies that
create new groups need to be careful to obey this restriction
(7.2.1). However, if a posting agent neglects to normalize a
newsgroup-name entered manually, this may lead to the user
posting to a non-existent group without understanding why.
Newsgroup-names containing non-ASCII characters MUST be encoded in
UTF-8. The use of [RFC 2047] encoding is inappropriate for reasons
explained in section 4.4.1.
Components beginning with underline ("_") are reserved for use by Components beginning with underline ("_") are reserved for use by
future versions of this standard and MUST NOT occur in newsgroup- future versions of this standard and MUST NOT occur in newsgroup-
names (whether in Newsgroups-headers or in newgroup control messages names (whether in Newsgroups-headers or in newgroup control messages
(7.2.1)). However, such names MUST be accepted. (7.2.1)). However, such names MUST be accepted.
Components beginning with "+" or "-" are reserved for use by Components beginning with "+" or "-" are reserved for use by
implementations and MUST NOT occur in newsgroup-names (whether in implementations and MUST NOT occur in newsgroup-names (whether in
Newsgroups-headers or in newgroup control messages). Implementors may Newsgroups-headers or in newgroup control messages). Implementors may
assume that this rule will not change in any future version of this assume that this rule will not change in any future version of this
standard. standard.
NOTE: For example, implementors may safely use leading "+" and NOTE: For example, implementors may safely use leading "+" and
"-" to "escape" other entities within something that looks like "-" to "escape" other entities within something that looks like
a newsgroup-name. a newsgroup-name.
Agencies responsible for the administration of particular hierarchies Agencies responsible for the administration of particular hierarchies
Ought to place additional restrictions on the characters they allow MAY place additional restrictions on the newsgroup-names they allow
in newsgroup-names within those hierarchies (such as to accord with within those hierarchies. Where there is no such specific policy, the
the languages commonly used within those hierarchies, or to avoid following restrictions SHOULD be applied to newsgroup-names.
perceived ambiguities pertinent to those languages). Where there is
no such specific policy, the following restrictions SHOULD be applied
to newsgroup-names.
NOTE: These restrictions are intended to reflect existing NOTE: These restrictions are intended to reflect existing
practice, with some additions to accommodate foreseeable practice, with some additions to accommodate foreseeable
enhancements, and are intended both to avoid certain technical enhancements, and are intended both to avoid certain technical
difficulties and to avoid unnecessary confusion. It may well be difficulties and to avoid unnecessary confusion. It may well be
News Article Format February 2003
that experience will allow future extensions to this standard to that experience will allow future extensions to this standard to
relax some or all of these restrictions. relax some or all of these restrictions.
The specific restrictions (to be applied in the absence of The specific restrictions (to be applied in the absence of
established policies to the contrary) are: established policies to the contrary) are:
1. The following characters are forbidden, subject to the comments News Article Format April 2003
and notes at the end of the list:
characters in category Cn (Other, Not assigned) [1]
characters in category Co (Other, Private Use) [2]
characters in category Lt (Letter, Titlecase) [3]
characters in category Lu (Letter, Uppercase) [3]
characters in category Me (Mark, Enclosing) [4]
characters in category Pd (Punctuation, Dash) [4][5]
characters in category Pe (Punctuation, Close) [4]
characters in category Pf (Punctuation, Final quote) [4]
characters in category Pi (Punctuation, Initial quote) [4]
characters in category Po (Punctuation, Other) [4]
characters in category Ps (Punctuation, Open) [4]
characters in category Sc (Symbol, Currency) [4]
characters in category Sk (Symbol, Modifier) [4]
characters in category Sm (Symbol, Math) [4][5]
characters in category So (Symbol, Other) [4]
[1] As new characters are added to Unicode, the code point moves
from category Cn to some other category. As stated above,
implementors should be prepared for this.
[2] Specific private use characters can be used within a hierarchy
or co-operating subnet that has agreed meanings for them.
[3] Traditionally, newsgroup-names have been written in lowercase.
Posting agents Ought Not to convert uppercase or titlecase
characters to the corresponding lowercase forms except under
the explicit instructions of the poster.
[4] Traditionally newsgroup-names have only used letters, digits,
and the three special characters "+", "-" and "_". These
categories correspond to characters outside that set.
[5] Although the characters "+" and "-" are within categories Pd 1. Uppercase letters are forbidden. Traditionally, newsgroup-names
and Sm, they are not forbidden. have been written in lowercase. Posting agents Ought Not to
convert uppercase characters to the corresponding lowercase forms
except under the explicit instructions of the poster.
2. A component name is forbidden to consist entirely of digits. 2. A component name is forbidden to consist entirely of digits.
NOTE: This requirement was in [RFC 1036] but nevertheless NOTE: This requirement was in [RFC 1036] but nevertheless
several such groups have appeared in practice and implementors several such groups have appeared in practice and implementors
should be prepared for them. A common implementation technique should be prepared for them. A common implementation technique
uses each component as the name of a directory and uses numeric uses each component as the name of a directory and uses numeric
filenames for each article within a group. Such an filenames for each article within a group. Such an
implementation needs to be careful when this could cause a clash implementation needs to be careful when this could cause a clash
(e.g. between article 123 of group xxx.yyy and the directory for (e.g. between article 123 of group xxx.yyy and the directory for
group xxx.yyy.123). group xxx.yyy.123).
News Article Format February 2003
3. A component is limited to 30 component-graphemes and a newsgroup- 3. A component is limited to 30 component-graphemes and a newsgroup-
name to 71 component-graphemes (counting also the '.'s separating name to 71 component-graphemes (counting also the '.'s separating
the components). Whilst there is no longer any technical reason to the components). Whilst there is no longer any technical reason
limit the length of a component (formerly, it was limited to 14 to limit the length of a component (formerly, it was limited to 14
octets) nor of a newsgroup-name, it should be noted that these octets) nor of a newsgroup-name, it should be noted that these
names are also used in the newsgroups-line (7.2.1.2) where an names are also used in the newsgroups-line (7.2.1.2) where an
overall policy limit applies and, moreover, excessively long names overall policy limit applies and, moreover, excessively long names
can be exceedingly inconvenient in practical use. can be exceedingly inconvenient in practical use.
Serving and relaying agents MUST accept any newsgroup-name that meets Serving and relaying agents MUST accept any newsgroup-name that meets
the above requirements, even if they violate one or more of the the above requirements, even if it violates one or more of the policy
policy restrictions. Posting and injecting agents MAY reject articles restrictions. Posting and injecting agents MAY reject articles
containing newsgroup-names that do not meet these restrictions, and containing newsgroup-names that do not meet these restrictions, and
posting agents MAY attempt to correct them (but only with the posting agents MAY attempt to correct them (but only with the
explicit agreement of the poster for anything more than NFC or NFKC explicit agreement of the poster).
normalization). However, because of the large and changing tables
required to do these checks and corrections throughout the whole of
Unicode, this standard does not require them to do so. Rather, the
onus is placed on those who create new newsgroups (7.2.1) to check
the mandatory requirements, to consider the effects of relaxing the
other restrictions, and to consider how all this may affect
propagation of the group.
Since future extensions to this standard and the Unicode standard, Since future extensions to this standard plus any relaxations of the
including a possible relaxation of the NFKC normalization, plus any default restrictions introduced by specific hierarchies might
relaxations of the default restrictions introduced by specific invalidate some such checks, warnings, and adjustments,
hierarchies might invalidate some such checks, warnings, and implementations MUST incorporate means to disable them.
adjustments, implementations MUST incorporate means to disable them.
NOTE: The newsgroup-name as encoded in UTF-8 should be regarded as NOTE: Observe that the syntax does not allow comments within the
the canonical form. Reading agents may convert it to whatever Newsgroups-header; this is to simplify processing by relaying and
character set they are able to display and serving agents may serving agents which have a requirement to process this header
possibly need to convert it to some form more suitable as a extremely rapidly.
filename. Simple algorithms for both kinds of conversion are
readily available. Observe that the syntax does not allow
comments within the Newsgroups-header; this is to simplify
processing by relaying and serving agents which have a requirement
to process this header extremely rapidly.
The inclusion of folding white space within a Newsgroups-content is a The inclusion of folding white space within a Newsgroups-content is a
newly introduced feature in this standard. It MUST be accepted by all newly introduced feature in this standard. It MUST be accepted by all
conforming implementations (relaying agents, serving agents and conforming implementations (relaying agents, serving agents and
reading agents). Posting agents should be aware that such postings reading agents). Posting agents should be aware that such postings
may be rejected by overly-critical old-style relaying agents. When a may be rejected by overly-critical old-style relaying agents. When a
sufficient number of relaying agents are in conformance, posting sufficient number of relaying agents are in conformance, posting
agents SHOULD generate such whitespace in the form of <CRLF WSP> so agents SHOULD generate such whitespace in the form of <CRLF WSP> so
as to keep the length of lines in the relevant headers (notably as to keep the length of lines in the relevant headers (notably
Newsgroups and Followup-To) to no more than than 79 characters (or Newsgroups and Followup-To) to no more than than 79 characters (or
other agreed policy limit - see 4.5). Before such critical mass other agreed policy limit - see 4.5). Before such critical mass
occurs, injecting agents MAY reformat such headers by removing occurs, injecting agents MAY reformat such headers by removing
whitespace inserted by the posting agent, but relaying agents MUST whitespace inserted by the posting agent, but relaying agents MUST
NOT do so. News Article Format April 2003
News Article Format February 2003 NOT do so.
Posters SHOULD use only the names of existing newsgroups in the Posters SHOULD use only the names of existing newsgroups in the
Newsgroups-header. However, it is legitimate to cross-post to Newsgroups-header. However, it is legitimate to cross-post to
newsgroups which do not exist on the posting agent's host, provided newsgroups which do not exist on the posting agent's host, provided
that at least one of the newsgroups DOES exist there, and followup that at least one of the newsgroups DOES exist there, and followup
agents SHOULD accept this (posting agents MAY accept it, but Ought at agents SHOULD accept this (posting agents MAY accept it, but Ought at
least to alert the poster to the situation and request confirmation). least to alert the poster to the situation and request confirmation).
Relaying agents MUST NOT rewrite Newsgroups-headers in any way, even Relaying agents MUST NOT rewrite Newsgroups-headers in any way, even
if some or all of the newsgroups do not exist on the relaying agent's if some or all of the newsgroups do not exist on the relaying agent's
host. Serving agents MUST NOT create new newsgroups simply because an host. Serving agents MUST NOT create new newsgroups simply because an
unrecognized newsgroup-name occurs in a Newsgroups-header (see 7.2.1 unrecognized newsgroup-name occurs in a Newsgroups-header (see 7.2.1
for the correct method of newsgroup creation). for the correct method of newsgroup creation).
The Newsgroups-header is intended for use in Netnews articles rather The Newsgroups-header is intended for use in Netnews articles rather
than in email messages. It MAY be used in an email message to than in email messages. It MAY be used in an email message to
indicate that it is a copy also posted to the listed newsgroups, in indicate that it is a copy also posted to the listed newsgroups, in
which case the inclusion of a Posted-And-Mailed header (6.9) would which case the inclusion of a Posted-And-Mailed header (6.9) would
also be appropriate. However, it SHOULD NOT be used in an email-only also be appropriate. However, it SHOULD NOT be used in an email-only
reply to a Netnews article (thus the "inheritable" property of this reply to a Netnews article (thus the "inheritable" property of this
header applies only to followups to a newsgroup, and not to followups header applies only to followups to a newsgroup, and not to followups
to the poster). Moreover, if a newsgroup-name contains any non-ASCII to the poster).
character, it may need to be encoded using the mechanism defined in
section 5.5.2. See also the further discussion in section 8.8.1.1.
5.5.1. Forbidden newsgroup-names 5.5.1. Forbidden newsgroup-names
The following forms of newsgroup-name MUST NOT be used except for the The following forms of newsgroup-name MUST NOT be used except for the
specific purposes indicated: specific purposes indicated:
o Newsgroup-names having only one component. These are reserved for o Newsgroup-names having only one component. These are reserved for
newsgroups whose propagation is restricted to a single host or newsgroups whose propagation is restricted to a single host or
local network, and for pseudo-newsgroups such as "poster" (which local network, and for pseudo-newsgroups such as "poster" (which
has special meaning in the Followup-To-header - see section 6.7), has special meaning in the Followup-To-header - see section 6.7),
skipping to change at page 41, line 56 skipping to change at page 35, line 55
o Any newsgroup-name beginning with "example." (reserved for o Any newsgroup-name beginning with "example." (reserved for
examples in this and other standards); examples in this and other standards);
o Any newsgroup-name containing the component "all" (because this o Any newsgroup-name containing the component "all" (because this
is used as a wildcard in some implementations). is used as a wildcard in some implementations).
A newsgroup-name SHOULD NOT appear more than once in the Newsgroups- A newsgroup-name SHOULD NOT appear more than once in the Newsgroups-
header. The order of newsgroup-names in the Newsgroups-header is not header. The order of newsgroup-names in the Newsgroups-header is not
significant, except for determining which moderator to send the significant, except for determining which moderator to send the
article to if more than one of the groups is moderated (see 8.2). article to if more than one of the groups is moderated (see 8.2).
5.5.2. Encoded newsgroup-names
Where it is required to transport an article across some medium that
cannot reliably convey the full 8 bits of each octet, such as when
gatewaying it into Email (8.8.1.1), or when emailing it to a
News Article Format February 2003
moderator or constructing the submission address of the moderator
(8.2.2), it will be necessary under the current email standards to
encode any newsgroup-name that contains some non-ASCII character
(such as one occurring within a Newsgroups- or Followup-To-header).
For that purpose, the following algorithm is provided:
1. Initially, the newsgroup-name is in the form of a sequence of
octets representing that name in the UTF-8 character set.
2. Each octet in the name in the range 0x80-FF is replaced by an "="
character (US-ASCII 61), followed by two characters representing
that octet in hexadecimal, in which the hexadecimal digits "A"
through "F" MUST be in uppercase.
3. Each octet in the name in the range 0x00-7F remains unaltered (and
thus MUST NOT be replaced by its hexadecimal equivalent).
NOTE: Observe that this algorithm provides a unique encoding for
each newsgroup-name. Observe also that within the unaltered
range 0x00-7F, only the octets 0x2B, 0x2D-2E, 0x30-39, 0x41-5A,
0x5F, and 0x61-7A can appear in a newsgroup-name.
This standard provides no authority for the use of this algorithm
other than in the context of newsgroup-names occurring within headers
being conveyed by email. In particular, it MUST NOT be used within
any article conveyed by the Netnews protocols and thus, if an email
using it is subsequently returned to the Netnews environment, it MUST
be decoded back into UTF-8.
5.6. Path 5.6. Path
The Path-header shows the route taken by a message since its entry The Path-header shows the route taken by a message since its entry
into the Netnews system. It is a variant header (4.2.5.3), each agent into the Netnews system. It is a variant header (4.2.5.3), each agent
that processes an article being required to add one (or more) entries that processes an article being required to add one (or more) entries
News Article Format April 2003
to it. This is primarily to enable relaying agents to avoid sending to it. This is primarily to enable relaying agents to avoid sending
articles to sites already known to have them, in particular the site articles to sites already known to have them, in particular the site
they came from, and additionally to permit tracing the route articles they came from, and additionally to permit tracing the route articles
take in moving over the network, and for gathering Usenet statistics. take in moving over the network, and for gathering Usenet statistics.
Finally the presence of a '%' path-delimiter in the Path-header can Finally the presence of a '%' path-delimiter in the Path-header can
be used to identify an article injected in conformance with this be used to identify an article injected in conformance with this
standard. standard.
5.6.1. Format 5.6.1. Format
header =/ Path-header header =/ Path-header
Path-header = "Path" ":" SP Path-content Path-header = "Path" ":" SP Path-content
*( ";" extension-parameter ) *( ";" extension-parameter )
Path-content = [FWS] Path-content = [FWS]
*( path-identity [FWS] path-delimiter [FWS] ) *( path-identity [FWS] path-delimiter [FWS] )
tail-entry [FWS] tail-entry [FWS]
path-identity = ( ALPHA / DIGIT ) path-identity = ( ALPHA / DIGIT )
*( ALPHA / DIGIT / "-" / "." / ":" / "_" ) *( ALPHA / DIGIT / "-" / "." / ":" / "_" )
path-delimiter = "/" / "?" / "%" / "," / "!" path-delimiter = "/" / "?" / "%" / "," / "!"
tail-entry = path-identity tail-entry = path-identity
News Article Format February 2003
NOTE: A Path-content will inevitably contain at least one path- NOTE: A Path-content will inevitably contain at least one path-
identity, except possibly in the case of a proto-article that identity, except possibly in the case of a proto-article that
has not yet been injected onto the network. has not yet been injected onto the network.
NOTE: Observe that the syntax does not allow comments within the NOTE: Observe that the syntax does not allow comments within the
Path-header; this is to simplify processing by relaying and Path-header; this is to simplify processing by relaying and
injecting agents which have a requirement to process this header injecting agents which have a requirement to process this header
extremely rapidly. extremely rapidly.
skipping to change at page 43, line 39 skipping to change at page 37, line 5
sites not wishing to act upon them. sites not wishing to act upon them.
5.6.2. Adding a path-identity to the Path-header 5.6.2. Adding a path-identity to the Path-header
When an injecting, relaying or serving agent receives an article, it When an injecting, relaying or serving agent receives an article, it
MUST prepend its own path-identity followed by a path-delimiter to MUST prepend its own path-identity followed by a path-delimiter to
the beginning of the Path-content. In addition, it SHOULD then add the beginning of the Path-content. In addition, it SHOULD then add
CRLF and WSP if it would otherwise result in a line longer than 79 CRLF and WSP if it would otherwise result in a line longer than 79
characters. characters.
News Article Format April 2003
The path-identity added MUST be unique to that agent. To this end it The path-identity added MUST be unique to that agent. To this end it
SHOULD be one of: SHOULD be one of:
1. A fully qualified domain name (FQDN) associated (by the Internet 1. A fully qualified domain name (FQDN) associated (by the Internet
DNS service [RFC 1034]) with an A record, which SHOULD identify DNS service [RFC 1034]) with an A record, which SHOULD identify
the actual machine prepending this path-identity. Ideally, this the actual machine prepending this path-identity. Ideally, this
FQDN should also be "mailable" (see below). FQDN should also be "mailable" (see below).
2. A fully qualified domain name (FQDN) associated (by the Internet 2. A fully qualified domain name (FQDN) associated (by the Internet
DNS service) with an MX record, which MUST be "mailable". DNS service) with an MX record, which MUST be "mailable".
3. An arbitrary name believed to be unique and registered at least 3. An arbitrary name believed to be unique and registered at least
with all sites immediately downstream from the given site. with all sites immediately downstream from the given site.
4. An encoding of an IP address - <IPv4address> or <IPv6address> [RFC 4. An encoding of an IP address - <IPv4address> or <IPv6address> [RFC
2373] (the requirement to be able to use an <IPv6address> is the 2373] (the requirement to be able to use an <IPv6address> is the
reason for including ':' as an allowed character within a path- reason for including ':' as an allowed character within a path-
identity). identity).
News Article Format February 2003
The FQDN of an agent is "mailable" if the administrators of that The FQDN of an agent is "mailable" if the administrators of that
agent can be reached by email using both of the forms "usenet@<FQDN>" agent can be reached by email using both of the forms "usenet@<FQDN>"
and "news@<FQDN>", in conformity with [RFC 2142]. and "news@<FQDN>", in conformity with [RFC 2142].
Of the above options, nos. 1 to 3 are much to be preferred, unless Of the above options, nos. 1 to 3 are much to be preferred, unless
there are strong technical reasons dictating otherwise. In there are strong technical reasons dictating otherwise. In
particular, the injecting agent's path-identity MUST, as a special particular, the injecting agent's path-identity MUST, as a special
case, be an FQDN as in option 1 or option 2, and MUST be mailable. case, be an FQDN as in option 1 or option 2, and MUST be mailable.
Additionally, in the case of an injecting agent offering its services Additionally, in the case of an injecting agent offering its services
to the general public, its administrators MUST also be reachable to the general public, its administrators MUST also be reachable
skipping to change at page 44, line 40 skipping to change at page 38, line 5
entries to the Path-content; firstly the true established path- entries to the Path-content; firstly the true established path-
identity of the source followed by a '?' path-delimiter, and then, identity of the source followed by a '?' path-delimiter, and then,
to the left of that, the agent's own path-identity followed by a '/' to the left of that, the agent's own path-identity followed by a '/'
path-delimiter as usual. This prepending of two entries SHOULD NOT path-delimiter as usual. This prepending of two entries SHOULD NOT
be done if the provided and established identities match. be done if the provided and established identities match.
Any method of establishing the identity of the source may be used Any method of establishing the identity of the source may be used
(but see 5.6.5 below), with the consideration that, in the event of (but see 5.6.5 below), with the consideration that, in the event of
problems, the agent concerned may be called upon to justify it. problems, the agent concerned may be called upon to justify it.
News Article Format April 2003
NOTE: The use of the '%' path-delimiter marks the position of NOTE: The use of the '%' path-delimiter marks the position of
the injecting agent in the chain. In normal circumstances there the injecting agent in the chain. In normal circumstances there
should therefore be only one '%' path-delimiter present, and should therefore be only one '%' path-delimiter present, and
injecting agents MAY choose to reject proto-articles with a '%' injecting agents MAY choose to reject proto-articles with a '%'
already in them. If, for whatever reason, more than one '%' is already in them. If, for whatever reason, more than one '%' is
found, then the path-identity in front of the leftmost '%' is to found, then the path-identity in front of the leftmost '%' is to
be regarded as the true injecting agent. be regarded as the true injecting agent.
5.6.3. The tail-entry 5.6.3. The tail-entry
For historical reasons, the tail-entry (i.e. the rightmost entry in For historical reasons, the tail-entry (i.e. the rightmost entry in
the Path-content) is regarded as a "user name", and therefore MUST the Path-content) is regarded as a "user name", and therefore MUST
NOT be interpreted as a site through which the article has already NOT be interpreted as a site through which the article has already
passed. Moreover, the Path-content as a whole is not an email address passed. Moreover, the Path-content as a whole is not an email address
and MUST NOT be used to contact the poster. Posting and/or injecting and MUST NOT be used to contact the poster. Posting and/or injecting
agents MAY place any string here. When it is not an actual user agents MAY place any string here. When it is not an actual user
name, the string "not-for-mail" is often used, but in fact a simple name, the string "not-for-mail" is often used, but in fact a simple
"x" would be sufficient. "x" would be sufficient.
News Article Format February 2003
Often this field will be the only entry in the region (known as the Often this field will be the only entry in the region (known as the
pre-injection region) after the '%', although there may be entries pre-injection region) after the '%', although there may be entries
corresponding to machines traversed between the posting agent and the corresponding to machines traversed between the posting agent and the
injecting agent proper. In particular, injecting agents that receive injecting agent proper. In particular, injecting agents that receive
articles from many sources MAY include information to establish the articles from many sources MAY include information to establish the
circumstances of the injection such as the identity of the source circumstances of the injection such as the identity of the source
machine (especially if an Injector-Info-header (6.19) is not being machine (especially if an Injector-Info-header (6.19) is not being
provided). Any such inclusion SHOULD NOT conflict with any genuine provided). Any such inclusion SHOULD NOT conflict with any genuine
site identifier. The '!' path-delimiter may be used freely within site identifier. The '!' path-delimiter may be used freely within
the pre-injection region, although '/' and '?' are also appropriate the pre-injection region, although '/' and '?' are also appropriate
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'?' The name immediately to the right is the claimed identity of the '?' The name immediately to the right is the claimed identity of the
machine from which the article was received, but we were unable machine from which the article was received, but we were unable
to verify it (and have prepended our own view of where it came to verify it (and have prepended our own view of where it came
from, and then a '/'). from, and then a '/').
'%' Everything to the right is the pre-injection region followed by '%' Everything to the right is the pre-injection region followed by
the tail-entry. The name on the left is the FQDN of the the tail-entry. The name on the left is the FQDN of the
injecting agent. The presence of two '%'s in a path indicates a injecting agent. The presence of two '%'s in a path indicates a
double-injection (see 8.2.2). double-injection (see 8.2.2).
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'!' The name immediately to the right is unverified. The presence of '!' The name immediately to the right is unverified. The presence of
a '!' to the left of the '%' indicates that the identity to the a '!' to the left of the '%' indicates that the identity to the
left is that of an old-style system not conformant with this left is that of an old-style system not conformant with this
standard. standard.
',' Reserved for future use, treat as '/'. ',' Reserved for future use, treat as '/'.
Other Other
Old software may possibly use other path-delimiters, which should Old software may possibly use other path-delimiters, which should
be treated as '!'. But note in particular that ':', '-' and '_' be treated as '!'. But note in particular that ':', '-' and '_'
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NOTE: Old Netnews relaying and injecting agents almost all NOTE: Old Netnews relaying and injecting agents almost all
delimit Path entries with a '!', and these entries are not delimit Path entries with a '!', and these entries are not
verified. The presence of '%' indicates that the article was verified. The presence of '%' indicates that the article was
injected by software conforming to this standard, and the injected by software conforming to this standard, and the
presence of '!' to the left of a '%' indicates that the message presence of '!' to the left of a '%' indicates that the message
passed through systems developed prior to this standard. It is passed through systems developed prior to this standard. It is
anticipated that relaying agents will reject articles in the old anticipated that relaying agents will reject articles in the old
style once this new standard has been widely adopted. style once this new standard has been widely adopted.
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5.6.5. Suggested Verification Methods 5.6.5. Suggested Verification Methods
It is preferable to verify the claimed path-identity against the It is preferable to verify the claimed path-identity against the
source than to make routine use of the '?' path-delimiter, with source than to make routine use of the '?' path-delimiter, with
consequential wasteful double-entry Path additions. consequential wasteful double-entry Path additions.
If the incoming article arrives through some TCP/IP protocol such as If the incoming article arrives through some TCP/IP protocol such as
NNTP, the IP address of the source will be known, and will likely NNTP, the IP address of the source will be known, and will likely
already have been checked against a list of known FQDNs, IP already have been checked against a list of known FQDNs, IP
addresses, or other registered aliases that the receiving site has addresses, or other registered aliases that the receiving site has
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UUCP, that protocol MUST include a means of verifying the source UUCP, that protocol MUST include a means of verifying the source
site. In UUCP implementations, commonly each incoming connection has site. In UUCP implementations, commonly each incoming connection has
a unique login name and password, and that login name (or some alias a unique login name and password, and that login name (or some alias
registered for it) would be expected as the path-identity. registered for it) would be expected as the path-identity.
5.6.6. Example 5.6.6. Example
Path: foo.isp.example/ Path: foo.isp.example/
foo-server/bar.isp.example?10.123.12.2/old.site.example! foo-server/bar.isp.example?10.123.12.2/old.site.example!
barbaz/baz.isp.example%dialup123.baz.isp.example!x barbaz/baz.isp.example%dialup123.baz.isp.example!x
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NOTE: That article was injected into the news stream by NOTE: That article was injected into the news stream by
baz.isp.example (complaints may be addressed to baz.isp.example (complaints may be addressed to
abuse@baz.isp.example). The injector has taken care to record abuse@baz.isp.example). The injector has taken care to record
that it got it from dialup123.baz.isp.example. "x" is a dummy that it got it from dialup123.baz.isp.example. "x" is a dummy
tail-entry, though sometimes a real userid is put there. tail-entry, though sometimes a real userid is put there.
The article was relayed, perhaps by UUCP, to the machine known, The article was relayed, perhaps by UUCP, to the machine known,
at least to its downstream, as "barbaz". at least to its downstream, as "barbaz".
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Old.site.example relayed it to a site claiming to have the IP Old.site.example relayed it to a site claiming to have the IP
address [10.123.12.2], and claiming (by using the '/' path- address [10.123.12.2], and claiming (by using the '/' path-
delimiter) to have verified that it came from old.site.example. delimiter) to have verified that it came from old.site.example.
[10.123.12.2] relayed it to "foo-server" which, not being [10.123.12.2] relayed it to "foo-server" which, not being
convinced that it truly came from [10.123.12.2], did a reverse convinced that it truly came from [10.123.12.2], did a reverse
lookup on the actual source and concluded it was known as lookup on the actual source and concluded it was known as
bar.isp.example (that is not to say that [10.123.12.2] was not a bar.isp.example (that is not to say that [10.123.12.2] was not a
correct IP address for bar.isp.example, but simply that that correct IP address for bar.isp.example, but simply that that
connection could not be substantiated by foo-server). Observe connection could not be substantiated by foo-server). Observe
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that foo-server has now added two entries to the Path. that foo-server has now added two entries to the Path.
"foo-server" is a locally significant name within the complex "foo-server" is a locally significant name within the complex
site of many machines run by foo.isp.example, so the latter site of many machines run by foo.isp.example, so the latter
should have no problem recognizing foo-server and using a '/' should have no problem recognizing foo-server and using a '/'
path-delimiter. Presumably foo.isp.example then delivered the path-delimiter. Presumably foo.isp.example then delivered the
article to its direct clients. article to its direct clients.
It appears that foo.isp.example and old.site.example decided to It appears that foo.isp.example and old.site.example decided to
fold the line, on the grounds that it seemed to be getting a fold the line, on the grounds that it seemed to be getting a
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specifically stated otherwise. Experimental headers (4.2.5.1) and specifically stated otherwise. Experimental headers (4.2.5.1) and
headers defined by cooperating subnets are exempt from this headers defined by cooperating subnets are exempt from this
requirement. See section 8 "Duties of Various Agents" for the full requirement. See section 8 "Duties of Various Agents" for the full
picture. picture.
6.1. Reply-To 6.1. Reply-To
The Reply-To-header specifies a reply address(es) to be used for The Reply-To-header specifies a reply address(es) to be used for
personal replies for the poster(s) of the article when this is personal replies for the poster(s) of the article when this is
different from the poster's address(es) given in the From-header. The different from the poster's address(es) given in the From-header. The
content syntax makes use of syntax defined in [RFC 2822], but subject content syntax makes use of syntax defined in [RFC 2822].
to the revised definition of local-part given in section 5.2.
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header =/ Reply-To-header header =/ Reply-To-header
Reply-To-header = "Reply-To" ":" SP Reply-To-content Reply-To-header = "Reply-To" ":" SP Reply-To-content
Reply-To-content = address-list Reply-To-content = address-list
In the absence of Reply-To, the reply address(es) is the address(es) In the absence of Reply-To, the reply address(es) is the address(es)
in the From-header. For this reason a Reply-To SHOULD NOT be included in the From-header. For this reason a Reply-To SHOULD NOT be included
if it just duplicates the From-header. if it just duplicates the From-header.
NOTE: Use of a Reply-To-header is preferable to including a NOTE: Use of a Reply-To-header is preferable to including a
similar request in the article body, because replying agents can similar request in the article body, because replying agents can
take account of Reply-To automatically. take account of Reply-To automatically.
6.1.1. Examples 6.1.1. Examples
Reply-To: John Smith <jsmith@site.example> Reply-To: John Smith <jsmith@site.example>
Reply-To: John Smith <jsmith@site.example>, dave@isp.example Reply-To: John Smith <jsmith@site.example>, dave@isp.example
Reply-To: John Smith <jsmith@site.example>,andrew@isp.example, Reply-To: John Smith <jsmith@site.example>,andrew@isp.example,
fred@site2.example fred@site2.example
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6.2. Sender 6.2. Sender
The Sender-header specifies the mailbox of the person or entity which The Sender-header specifies the mailbox of the person or entity which
caused this article to be posted (and hence injected), if that person caused this article to be posted (and hence injected), if that person
or entity is different from that given in the From-header or if more or entity is different from that given in the From-header or if more
than one mailbox appears in the From-header. This header SHOULD NOT than one mailbox appears in the From-header. This header SHOULD NOT
appear in an article unless the sender is different from the poster. appear in an article unless the sender is different from the poster.
This header is appropriate for use by automatic article posters. The This header is appropriate for use by automatic article posters. The
content syntax makes use of syntax defined in [RFC 2822], subject to content syntax makes use of syntax defined in [RFC 2822].
the revised definition of local-part given in section 5.2.
header =/ Sender-header header =/ Sender-header
Sender-header = "Sender" ":" SP Sender-content Sender-header = "Sender" ":" SP Sender-content
Sender-content = mailbox Sender-content = mailbox
6.3. Organization 6.3. Organization
The Organization-header is a short phrase identifying the poster's The Organization-header is a short phrase identifying the poster's
organization. organization.
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acceptable to all posters using those agents. Unless this header acceptable to all posters using those agents. Unless this header
contains useful information (including some indication of the contains useful information (including some indication of the
posters physical location) posters are discouraged from posters physical location) posters are discouraged from
including it. including it.
6.4. Keywords 6.4. Keywords
The Keywords field contains a comma separated list of important words The Keywords field contains a comma separated list of important words
and phrases intended to describe some aspect of the content of the and phrases intended to describe some aspect of the content of the
article. The content syntax makes use of syntax defined in [RFC article. The content syntax makes use of syntax defined in [RFC
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2822]. 2822].
header =/ Keywords-header header =/ Keywords-header
Keywords-header = "Keywords" ":" SP Keywords-content Keywords-header = "Keywords" ":" SP Keywords-content
Keywords-content = phrase *( "," phrase ) Keywords-content = phrase *( "," phrase )
NOTE: The list is comma separated, NOT space separated. NOTE: The list is comma separated, NOT space separated.
NOTE: Contrary to the usage defined in [RFC 2822], this standard NOTE: Contrary to the usage defined in [RFC 2822], this standard
does not permit multiple occurrences of this header. does not permit multiple occurrences of this header.
6.5. Summary 6.5. Summary
The Summary-header is a short phrase summarizing the article's The Summary-header is a short phrase summarizing the article's
content. content.
header =/ Summary-header header =/ Summary-header
Summary-header = "Summary" ":" SP Summary-content Summary-header = "Summary" ":" SP Summary-content
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Summary-content = unstructured Summary-content = unstructured
The summary should be terse. Authors Ought to avoid trying to cram The summary should be terse. Authors Ought to avoid trying to cram
their entire article into the headers; even the simplest query their entire article into the headers; even the simplest query
usually benefits from a sentence or two of elaboration and context, usually benefits from a sentence or two of elaboration and context,
and not all reading agents display all headers. On the other hand the and not all reading agents display all headers. On the other hand the
summary should give more detail than the Subject. summary should give more detail than the Subject.
6.6. Distribution 6.6. Distribution
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header =/ Distribution-header header =/ Distribution-header
Distribution-header = "Distribution" ":" SP Distribution-content Distribution-header = "Distribution" ":" SP Distribution-content
*( ";" extension-parameter ) *( ";" extension-parameter )
Distribution-content= distribution *( dist-delim distribution ) Distribution-content= distribution *( dist-delim distribution )
dist-delim = "," dist-delim = ","
distribution = [FWS] distribution-name [FWS] distribution = [FWS] distribution-name [FWS]
distribution-name = ALPHA 1*distribution-rest distribution-name = ALPHA 1*distribution-rest
distribution-rest = ALPHA / "+" / "-" / "_" distribution-rest = ALPHA / "+" / "-" / "_"
NOTE: The use of ALPHA in the syntax ensures that distribution
names are always in US-ASCII.
Articles MUST NOT be passed between relaying agents or to serving Articles MUST NOT be passed between relaying agents or to serving
agents unless the sending agent has been configured to supply and the agents unless the sending agent has been configured to supply and the
receiving agent to receive at least one of the distributions in the receiving agent to receive at least one of the distributions in the
Distribution-header. Additionally, reading agents MAY also be Distribution-header. Additionally, reading agents MAY also be
configured so that unwanted distributions do not get displayed. configured so that unwanted distributions do not get displayed.
NOTE: Although it would seem redundant to filter out unwanted NOTE: Although it would seem redundant to filter out unwanted
distributions at both ends of a relaying link (and it is clearly distributions at both ends of a relaying link (and it is clearly
more efficient to do so at the sending end), many sending sites more efficient to do so at the sending end), many sending sites
have been reluctant, historically speaking, to apply such have been reluctant, historically speaking, to apply such
filters (except to ensure that distributions local to their own filters (except to ensure that distributions local to their own
site or cooperating subnet did not escape); moreover they tended site or cooperating subnet did not escape); moreover they tended
to configure their filters on an "all but those listed" basis, to configure their filters on an "all but those listed" basis,
News Article Format April 2003
so that new and hitherto unheard of distributions would not be so that new and hitherto unheard of distributions would not be
caught. Indeed many "hub" sites actually wanted to receive all caught. Indeed many "hub" sites actually wanted to receive all
possible distributions so that they could feed on to their possible distributions so that they could feed on to their
clients in all possible geographical (or organizational) clients in all possible geographical (or organizational)
regions. regions.
Therefore, it is desirable to provide facilities for rejecting Therefore, it is desirable to provide facilities for rejecting
unwanted distributions at the receiving end. Indeed, it may be unwanted distributions at the receiving end. Indeed, it may be
simpler to do so locally than to inform each sending site of simpler to do so locally than to inform each sending site of
what is required, especially in the case of specialized what is required, especially in the case of specialized
distributions (for example for control messages, such as cancels distributions (for example for control messages, such as cancels
from certain issuers) which might need to be added at short from certain issuers) which might need to be added at short
notice. The possibility for reading agents to filter notice. The possibility for reading agents to filter
distributions has been provided for the same reason. distributions has been provided for the same reason.
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Exceptionally, ALL relaying agents are deemed willing to supply or Exceptionally, ALL relaying agents are deemed willing to supply or
accept the distribution "world", and NO relaying agent should supply accept the distribution "world", and NO relaying agent should supply
or accept the distribution "local". However, "world" SHOULD NEVER be or accept the distribution "local". However, "world" SHOULD NEVER be
mentioned explicitly since it is the default when the Distribution- mentioned explicitly since it is the default when the Distribution-
header is absent entirely. "All" MUST NOT be used as a header is absent entirely. "All" MUST NOT be used as a
distribution-name. Distribution-names SHOULD contain at least three distribution-name. Distribution-names SHOULD contain at least three
characters, except when they are two-letter country names as in [ISO characters, except when they are two-letter country names as in [ISO
3166]. Distribution-names are case-insensitive (i.e. "US", "Us" and 3166]. Distribution-names are case-insensitive (i.e. "US", "Us" and
"us" all specify the same distribution). "us" all specify the same distribution).
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header =/ Followup-To-header header =/ Followup-To-header
Followup-To-header = "Followup-To" ":" SP Followup-To-content Followup-To-header = "Followup-To" ":" SP Followup-To-content
*( ";" extension-parameter ) *( ";" extension-parameter )
Followup-To-content = Newsgroups-content / Followup-To-content = Newsgroups-content /
[FWS] %x70.6F.73.74.65.72 [FWS] [FWS] %x70.6F.73.74.65.72 [FWS]
; which is a case-sensitive "poster" ; which is a case-sensitive "poster"
The syntax is the same as that of the Newsgroups-content, with the The syntax is the same as that of the Newsgroups-content, with the
addition that the keyword "poster" is allowed. In the absence of a addition that the keyword "poster" is allowed. In the absence of a
Followup-To-header, the default newsgroup(s) for a followup are those Followup-To-content, the default newsgroup(s) for a followup are
in the Newsgroups-header, and for this reason the Followup-To-header those in the Newsgroups-header, and for this reason the Followup-To-
SHOULD NOT be included if it just duplicates the Newsgroups-header. header SHOULD NOT be included if it just duplicates the Newsgroups-
header.
A Followup-To-header consisting of the keyword "poster" indicates A Followup-To-header consisting of the keyword "poster" indicates
that the poster requests no followups to be sent in response to this that the poster requests no followups to be sent in response to this
article, only personal replies to the article's reply address. article, only personal replies to the article's reply address.
Although the keyword "poster" is case-sensitive, followup agents MAY Although the keyword "poster" is case-sensitive, followup agents MAY
choose to regognize case insensitive forms such as "Poster". choose to regognize case insensitive forms such as "Poster".
News Article Format April 2003
NOTE: A poster who wishes both a personal reply and a followup NOTE: A poster who wishes both a personal reply and a followup
post should include an appropriate Mail-Copies-To-header (6.8). post should include an appropriate Mail-Copies-To-header (6.8).
6.8. Mail-Copies-To 6.8. Mail-Copies-To
The Mail-Copies-To-header indicates whether or not the poster wishes The Mail-Copies-To-header indicates whether or not the poster wishes
to have followups to an article emailed in addition to being posted to have followups to an article emailed in addition to being posted
to Netnews and, if so, establishes the address to which they should to Netnews and, if so, establishes the address to which they should
be sent. be sent.
The content syntax makes use of syntax defined in [RFC 2822], but The content syntax makes use of syntax defined in [RFC 2822].
subject to the revised definition of local-part given in section 5.2.
header =/ Mail-Copies-To-header header =/ Mail-Copies-To-header
News Article Format February 2003
Mail-Copies-To-header Mail-Copies-To-header
= "Mail-Copies-To" ":" SP Mail-Copies-To-content = "Mail-Copies-To" ":" SP Mail-Copies-To-content
Mail-Copies-To-content Mail-Copies-To-content
= copy-addr / [CFWS] ( "nobody" / "poster" ) [CFWS] = copy-addr / [CFWS] ( "nobody" / "poster" ) [CFWS]
copy-addr = address-list copy-addr = address-list
The keyword "nobody" indicates that the poster does not wish copies The keyword "nobody" indicates that the poster does not wish copies
of any followup postings to be emailed. This indication is widely of any followup postings to be emailed. This indication is widely
seen as a very strong wish, and is to be taken as the default when seen as a very strong wish, and is to be taken as the default when
this header is absent. this header is absent.
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then be sent to the address(es) in the Reply-To-header, and in the then be sent to the address(es) in the Reply-To-header, and in the
absence of that to the address(es) in the From-header. absence of that to the address(es) in the From-header.
copy-addr copy-addr
The followup agent Ought, by default, to email a copy, which MUST The followup agent Ought, by default, to email a copy, which MUST
then be sent to the copy-addr. then be sent to the copy-addr.
NOTE: This header is only relevant when posting followups to NOTE: This header is only relevant when posting followups to
Netnews articles, and is to be ignored when sending pure email Netnews articles, and is to be ignored when sending pure email
replies to the poster, which are handled as prescribed under the replies to the poster, which are handled as prescribed under the
News Article Format April 2003
Reply-To-header (6.1). Whether or not this header will also Reply-To-header (6.1). Whether or not this header will also
find similar usage for replies to messages sent to mailing lists find similar usage for replies to messages sent to mailing lists
falls outside the scope of this standard. falls outside the scope of this standard.
When emailing a copy, the followup agent SHOULD also include a When emailing a copy, the followup agent SHOULD also include a
"Posted-And-Mailed: yes" header (6.9). "Posted-And-Mailed: yes" header (6.9).
NOTE: In addition to the Posted-And-Mailed-header, some followup NOTE: In addition to the Posted-And-Mailed-header, some followup
agents also include within the body a mention that the article agents also include within the body a mention that the article
is both posted and mailed, for the benefit of reading agents is both posted and mailed, for the benefit of reading agents
that do not normally show that header. that do not normally show that header.
News Article Format February 2003
6.9. Posted-And-Mailed 6.9. Posted-And-Mailed
header =/ Posted-And-Mailed-header header =/ Posted-And-Mailed-header
Posted-And-Mailed-header Posted-And-Mailed-header
= "Posted-And-Mailed" ":" SP Posted-And-Mailed-content = "Posted-And-Mailed" ":" SP Posted-And-Mailed-content
*( ";" extension-parameter ) *( ";" extension-parameter )
Posted-And-Mailed-content Posted-And-Mailed-content
= [CFWS] ( "yes" / "no" ) [CFWS] = [CFWS] ( "yes" / "no" ) [CFWS]
This header, when used with the "yes" keyword, indicates that the This header, when used with the "yes" keyword, indicates that the
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identified in a To- and/or Cc-header that is also present. The "no" identified in a To- and/or Cc-header that is also present. The "no"
keyword is included for the sake of completeness; it MAY be used to keyword is included for the sake of completeness; it MAY be used to
indicate the opposite state, but is redundant insofar as it only indicate the opposite state, but is redundant insofar as it only
describes the default state when this header is absent. describes the default state when this header is absent.
This header, if present, MUST be included in both the posted and This header, if present, MUST be included in both the posted and
emailed versions of the article. The Newsgroups-header of the posted emailed versions of the article. The Newsgroups-header of the posted
article SHOULD be included in the email version as recommended in article SHOULD be included in the email version as recommended in
section 5.5. All other headers defined in this standard (excluding section 5.5. All other headers defined in this standard (excluding
variant headers) MUST be identical in both the posted and mailed variant headers) MUST be identical in both the posted and mailed
versions of the article, except that where they contain UTF8-xtra- versions of the article. The bodies MUST be identical in both, apart
chars, which in the mailed version MUST, to comply with section from a possible change of Content-Transfer-Encoding.
8.8.1.1, be encoded according to [RFC 2047] or [RFC 2231], or (in the
case of headers containing a newsgroup-name) to section 5.5.2, they
MAY, in the posted version, remain in UTF-8. The bodies MUST be
identical in both, apart from a possible change of Content-Transfer-
Encoding.
NOTE: This leaves open the question of whether a To- or a Cc- NOTE: This leaves open the question of whether a To- or a Cc-
header should appear in the posted version. Naturally, a Bcc- header should appear in the posted version. Naturally, a Bcc-
header should not appear, except in a form which indicates that header should not appear, except in a form which indicates that
there are additional unspecified recipients. there are additional unspecified recipients.
6.10. References 6.10. References
The References-header lists CFWS-separated message identifiers of The References-header lists CFWS-separated message identifiers of
precursors. The content syntax makes use of syntax defined in [RFC precursors. The content syntax makes use of syntax defined in [RFC
2822], subject to the same revisions as in section 5.3. 2822], subject to the same revisions as in section 5.3.
header =/ References-header header =/ References-header
References-header = "References" ":" SP References-content References-header = "References" ":" SP References-content
References-content = [CFWS] msg-id *( CFWS msg-id ) [CFWS] References-content = [CFWS] msg-id *( CFWS msg-id ) [CFWS]
News Article Format April 2003
NOTE: This differs from the syntax of [RFC 2822] by requiring at NOTE: This differs from the syntax of [RFC 2822] by requiring at
least one CFWS between the msg-ids (a SP at this point was an least one CFWS between the msg-ids (a SP at this point was an
[RFC 1036] requirement). [RFC 1036] requirement).
A followup MUST have a References-header, and an article that is not A followup MUST have a References-header, and an article that is not
a followup MUST NOT have a References-header. In a followup, if the a followup MUST NOT have a References-header. In a followup, if the
precursor did not have a References-header, the followup's precursor did not have a References-header, the followup's
News Article Format February 2003
References-content MUST be formed by the message identifier of the References-content MUST be formed by the message identifier of the
precursor. A followup to an article which had a References-header precursor. A followup to an article which had a References-header
MUST have a References-header containing the precursor's References- MUST have a References-header containing the precursor's References-
content (subject to trimming as described below) plus the precursor's content (subject to trimming as described below) plus the precursor's
message identifier appended to the end of the list (separated from it message identifier appended to the end of the list (separated from it
by CFWS). by CFWS).
Followup agents SHOULD NOT trim message identifiers out of a Followup agents SHOULD NOT trim message identifiers out of a
References-header unless the number of message identifiers exceeds References-header unless the number of message identifiers exceeds
21, at which time trimming SHOULD be done by removing sufficient 21, at which time trimming SHOULD be done by removing sufficient
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Expires-header = "Expires" ":" SP Expires-content Expires-header = "Expires" ":" SP Expires-content
*( ";" extension-parameter ) *( ";" extension-parameter )
Expires-content = date-time Expires-content = date-time
An Expires-header should only be used in an article if the requested An Expires-header should only be used in an article if the requested
expiry time is earlier or later than the time typically to be expiry time is earlier or later than the time typically to be
expected for such articles. Local policy for each serving agent will expected for such articles. Local policy for each serving agent will
dictate whether and when this header is obeyed and posters SHOULD NOT dictate whether and when this header is obeyed and posters SHOULD NOT
depend on it being completely followed. depend on it being completely followed.
News Article Format April 2003
6.12. Archive 6.12. Archive
This optional header provides an indication of the poster's intent This optional header provides an indication of the poster's intent
regarding preservation of the article in publicly accessible long- regarding preservation of the article in publicly accessible long-
term or permanent storage. term or permanent storage.
header =/ Archive-header header =/ Archive-header
Archive-header = "Archive" ":" SP Archive-content Archive-header = "Archive" ":" SP Archive-content
*( ";" ( Archive-parameter / *( ";" ( Archive-parameter /
extension-parameter ) ) extension-parameter ) )
Archive-content = [CFWS] ("no" / "yes" ) [CFWS] Archive-content = [CFWS] ("no" / "yes" ) [CFWS]
News Article Format February 2003
Archive-parameter = <a parameter with attribute "filename" Archive-parameter = <a parameter with attribute "filename"
and any value> and any value>
The presence of an "Archive: no" header in an article indicates that The presence of an "Archive: no" header in an article indicates that
the poster does not permit redistribution from publicly accessible the poster does not permit redistribution from publicly accessible
long-term or permanent archives. The absence of this header, or an long-term or permanent archives. The absence of this header, or an
explicit "Archive: yes", indicates that the poster is willing for explicit "Archive: yes", indicates that the poster is willing for
such redistribution to take place. The optional "filename" parameter such redistribution to take place. The optional "filename" parameter
can then be used to suggest a filename under which the article should can then be used to suggest a filename under which the article should
be stored. Further extensions to this standard may provide additional be stored. Further extensions to this standard may provide additional
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*( ";" extension-parameter ) *( ";" extension-parameter )
Control-content = [CFWS] control-message [CFWS] Control-content = [CFWS] control-message [CFWS]
control-message = <empty> control-message = <empty>
However, the rule given above for control-message is incomplete. However, the rule given above for control-message is incomplete.
Further alternatives will be added incrementally as the various Further alternatives will be added incrementally as the various
control-messages are introduced in section 7, or in extensions to control-messages are introduced in section 7, or in extensions to
this standard, using the "=/" notation defined in [RFC 2234]. For this standard, using the "=/" notation defined in [RFC 2234]. For
example, a typical CONTROL-message would be defined as follows: example, a typical CONTROL-message would be defined as follows:
News Article Format April 2003
control-message =/ CONTROL-message control-message =/ CONTROL-message
CONTROL-message = "CONTROL" CONTROL-arguments CONTROL-message = "CONTROL" CONTROL-arguments
CONTROL-arguments = <the argument(s) specific to that CONTROL-arguments = <the argument(s) specific to that
CONTROL-message> CONTROL-message>
where "CONTROL" is a "verb" which is (and MUST be) of the syntactic where "CONTROL" is a "verb" which is (and MUST be) of the syntactic
form of a token and CONTROL-arguments MUST be of the syntactic form form of a token and CONTROL-arguments MUST be of the syntactic form
of a CFWS-separated list of values (which may require the use of of a CFWS-separated list of values (which may require the use of
quoted-strings if any tspecials or non-ASCII characters are quoted-strings if any tspecials or non-ASCII characters are
involved). involved).
News Article Format February 2003
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 of the article may (if any) supply details. In some cases, the body of the article may
also contain details. also contain details.
An article with a Control-header MUST NOT also have a Supersedes- An article with a Control-header MUST NOT also have a Supersedes-
header. header.
NOTE: The presence of a Subject-header starting with the string NOTE: The presence of a Subject-header starting with the string
"cmsg " and followed by a Control-message MUST NOT be construed, "cmsg " and followed by a Control-message MUST NOT be construed,
in the absence of a proper Control-header, as a request to in the absence of a proper Control-header, as a request to
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An Approved-header is also required in certain control messages, to An Approved-header is also required in certain control messages, to
reduce the risks of accidental or unauthorized posting of same. reduce the risks of accidental or unauthorized posting of same.
NOTE: The presence of an Approved-header indicates that the NOTE: The presence of an Approved-header indicates that the
person or entity identified claims to have the necessary person or entity identified claims to have the necessary
authority to post the article in question, thus enabling sites authority to post the article in question, thus enabling sites
that dispute that authority to refuse to accept or to act upon that dispute that authority to refuse to accept or to act upon
it. However, the mere presence of the header is insufficient to it. However, the mere presence of the header is insufficient to
provide assurance that it indeed originated from that person or provide assurance that it indeed originated from that person or
News Article Format April 2003
entity, and it is therefore desirable that it be included within entity, and it is therefore desirable that it be included within
some digital signature scheme (see 7.1), especially in the case some digital signature scheme (see 7.1), especially in the case
of control messages (section 7). of control messages (section 7).
6.15. Supersedes 6.15. Supersedes
The Supersedes-header contains a message identifier specifying an The Supersedes-header contains a message identifier specifying an
article to be superseded upon the arrival of this one. The specified article to be superseded upon the arrival of this one. The specified
article MUST be treated as though a "cancel" control message had article MUST be treated as though a "cancel" control message had
arrived for the article (but observe that a site MAY choose not to arrived for the article (but observe that a site MAY choose not to
honour a "cancel" message, especially if its authenticity is in honour a "cancel" message, especially if its authenticity is in
News Article Format February 2003
doubt). The content syntax makes use of syntax defined in [RFC 2822], doubt). The content syntax makes use of syntax defined in [RFC 2822],
subject to the same revisions as in 5.3. subject to the same revisions as in 5.3.
header =/ Supersedes-header header =/ Supersedes-header
Supersedes-header = "Supersedes" ":" SP Supersedes-content Supersedes-header = "Supersedes" ":" SP Supersedes-content
Supersedes-content = [CFWS] msg-id [CFWS] Supersedes-content = [CFWS] msg-id [CFWS]
NOTE: There is no "c" in "Supersedes". NOTE: There is no "c" in "Supersedes".
NOTE: The Supersedes-header defined here has no connection with NOTE: The Supersedes-header defined here has no connection with
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header =/ Xref-header header =/ Xref-header
Xref-header = "Xref" ":" SP Xref-content Xref-header = "Xref" ":" SP Xref-content
*( ";" extension-parameter ) *( ";" extension-parameter )
Xref-content = [CFWS] server-name 1*( CFWS location ) [CFWS] Xref-content = [CFWS] server-name 1*( CFWS location ) [CFWS]
server-name = path-identity ; see 5.6.1 server-name = path-identity ; see 5.6.1
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 ';'
News Article Format April 2003
The server-name is included so that software can determine which The server-name is included so that software can determine which
serving agent generated the header. The locations specify what serving agent generated the header. The locations specify what
newsgroups the article was filed under (which may differ from those newsgroups the article was filed under (which may differ from those
in the Newsgroups-header) and where it was filed under them. The in the Newsgroups-header) and where it was filed under them. The
exact form of an article-locator is implementation-specific. exact form of an article-locator is implementation-specific.
NOTE: The traditional form of an article-locator is a decimal NOTE: The traditional form of an article-locator is a decimal
number, with articles in each newsgroup numbered consecutively number, with articles in each newsgroup numbered consecutively
starting from 1. NNTP demands that such a model be provided, and starting from 1. NNTP demands that such a model be provided, and
much other software expects it, but it seems desirable to permit much other software expects it, but it seems desirable to permit
flexibility for unorthodox implementations. flexibility for unorthodox implementations.
News Article Format February 2003
An agent inserting an Xref-header into an article MUST delete any An agent inserting an Xref-header into an article MUST delete any
previous Xref-header(s). A relaying agent MAY delete it before previous Xref-header(s). A relaying agent MAY delete it before
relaying, but otherwise it SHOULD be ignored by any relaying or relaying, but otherwise it SHOULD be ignored by any relaying or
serving agent receiving it. serving agent receiving it.
It is convenient, though not required, for a serving agent to use the It is convenient, though not required, for a serving agent to use the
same server-name in Xref-headers as the path-identity it uses in same server-name in Xref-headers as the path-identity it uses in
Path-headers (just so long as reading agents can distinguish it from Path-headers (just so long as reading agents can distinguish it from
other serving agents known to them). other serving agents known to them).
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6.18. User-Agent 6.18. User-Agent
The User-Agent-header contains information about the user agent The User-Agent-header 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
needing correction. Although not one of the mandatory headers, needing correction. Although not one of the mandatory headers,
posting agents SHOULD normally include it. It is also intended that posting agents SHOULD normally include it. It is also intended that
this header be suitable for use in Email. this header be suitable for use in Email.
News Article Format April 2003
header =/ User-Agent-header header =/ User-Agent-header
User-Agent-header = "User-Agent" ":" SP User-Agent-content User-Agent-header = "User-Agent" ":" SP User-Agent-content
*( ";" extension-parameter ) *( ";" extension-parameter )
User-Agent-content = product *( CFWS product ) User-Agent-content = product *( CFWS product )
product = [CFWS] token [CFWS] [ "/" product-version ] product = [CFWS] token [CFWS] [ "/" product-version ]
product-version = [CFWS] token [CFWS] product-version = [CFWS] token [CFWS]
This header MAY contain multiple product-tokens identifying the agent This header MAY contain multiple product-tokens identifying the agent
and any subproducts which form a significant part of the posting and any subproducts which form a significant part of the posting
agent, listed in order of their significance for identifying the agent, listed in order of their significance for identifying the
application. Product-tokens should be short and to the point - they application. Product-tokens should be short and to the point - they
MUST NOT be used for information beyond the canonical name of the MUST NOT be used for information beyond the canonical name of the
product and its version. Injecting agents MAY include product product and its version. Injecting agents MAY include product
News Article Format February 2003
information for themselves (such as "INN/1.7.2"), but relaying and information for themselves (such as "INN/1.7.2"), but relaying and
serving agents MUST NOT generate or modify this header to list serving agents MUST NOT generate or modify this header to list
themselves. themselves.
NOTE: A product, being composed of a token, can contain only
US-ASCII characters. Where the full name of an agent is
expressed in a language requiring non-ASCII characters, it is
suggested that an arbitrary (but easily recognizable) US_ASCII
token be provided, followed by the full name in the form of a
comment.
NOTE: Minor variations from [RFC 2616] which describes a similar NOTE: Minor variations from [RFC 2616] which describes a similar
facility for the HTTP protocol: facility for the HTTP protocol:
1. "{" and "}" are allowed in a token (product and product- 1. "{" and "}" are allowed in a token (product and product-
version) in Netnews, version) in Netnews,
2. Comments are permitted wherever whitespace is allowed. 2. Comments are permitted wherever whitespace is allowed.
NOTE: Comments should be restricted to information regarding the NOTE: Comments should be restricted to information regarding the
product named to their left, such as its full name or platform product named to their left, such as its full name or platform
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User-Agent: inn/1.7.2 User-Agent: inn/1.7.2
User-Agent: telnet User-Agent: telnet
NOTE: This header supersedes the role performed redundantly by NOTE: This header supersedes the role performed redundantly by
experimental headers such as X-Newsreader, X-Mailer, X-Posting- experimental headers such as X-Newsreader, X-Mailer, X-Posting-
Agent, X-Http-User-Agent, and other headers previously used on Agent, X-Http-User-Agent, and other headers previously used on
Usenet and in Email for this purpose. Use of these experimental Usenet and in Email for this purpose. Use of these experimental
headers SHOULD be discontinued in favor of the single, standard headers SHOULD be discontinued in favor of the single, standard
User-Agent-header. User-Agent-header.
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6.19. Injector-Info 6.19. Injector-Info
The Injector-Info-header SHOULD be added to each article by the The Injector-Info-header SHOULD be added to each article by the
injecting agent in order to provide information as to how that injecting agent in order to provide information as to how that
article entered the Netnews system and to assist in tracing its true article entered the Netnews system and to assist in tracing its true
origin. origin.
header =/ Injector-Info-header header =/ Injector-Info-header
News Article Format February 2003
Injector-Info-header Injector-Info-header
= "Injector-Info" ":" SP Injector-Info-content = "Injector-Info" ":" SP Injector-Info-content
*( ";" ( Injector-Info-parameter / *( ";" ( Injector-Info-parameter /
extension-parameter ) ) extension-parameter ) )
Injector-Info-content Injector-Info-content
= [CFWS] path-identity [CFWS] = [CFWS] path-identity [CFWS]
Injector-Info-parameter Injector-Info-parameter
= posting-host-parameter / = posting-host-parameter /
posting-account-parameter / posting-account-parameter /
posting-sender-parameter / posting-sender-parameter /
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an article arrives at an injecting agent MUST be removed. In an article arrives at an injecting agent MUST be removed. In
particular if, for some exceptional reason (8.2.2), an article gets particular if, for some exceptional reason (8.2.2), an article gets
injected twice, the Injector-Info-header will always relate to the injected twice, the Injector-Info-header will always relate to the
second injection. second injection.
The path-identity MUST be the same as the path-identity prepended to The path-identity MUST be the same as the path-identity prepended to
the Path-header by that same injecting agent which, following section the Path-header by that same injecting agent which, following section
5.6.2, MUST therefore be a fully qualified domain name (FQDN) 5.6.2, MUST therefore be a fully qualified domain name (FQDN)
mailable address. mailable address.
News Article Format April 2003
Although comments and folding of white space are permitted throughout Although comments and folding of white space are permitted throughout
the Injector-Info-content specification, it is RECOMMENDED that the Injector-Info-content specification, it is RECOMMENDED that
folding is not used within any parameter (but only before or after folding is not used within any parameter (but only before or after
the ";" separating those parameters), and that comments are only used the ";" separating those parameters), and that comments are only used
following the last parameter. It is also RECOMMENDED that such following the last parameter. It is also RECOMMENDED that such
parameters as are present are included in the order in which they parameters as are present are included in the order in which they
have been defined in the syntax above. An injecting agent SHOULD use have been defined in the syntax above. An injecting agent SHOULD use
a consistent form of this header for all articles emanating from the a consistent form of this header for all articles emanating from the
same or similar origins. same or similar origins.
News Article Format February 2003
NOTE: The effect of those recommendations is to facilitate the NOTE: The effect of those recommendations is to facilitate the
recognition of articles arising from certain designated origins recognition of articles arising from certain designated origins
(as in the so-called "killfiles" which are available in some (as in the so-called "killfiles" which are available in some
reading agents). Observe that the order within the syntax has reading agents). Observe that the order within the syntax has
been chosen to place last those parameters which are most likely been chosen to place last those parameters which are most likely
to change between successive articles posted from the same to change between successive articles posted from the same
origin. origin.
NOTE: To comply with the overall "attribute = value" syntax of NOTE: To comply with the overall "attribute = value" syntax of
parameters, any value containing an IPv6address, a date-time, a parameters, any value containing an IPv6address, a date-time, a
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there is no benefit in including parameters which contribute there is no benefit in including parameters which contribute
nothing to this aim). An administrator MAY, with those parameters nothing to this aim). An administrator MAY, with those parameters
where the syntax so allows, use cryptic notations interpretable where the syntax so allows, use cryptic notations interpretable
only by himself if he considers it appropriate to protect the only by himself if he considers it appropriate to protect the
privacy of that origin. privacy of that origin.
2. To enable relaying, serving and reading agents to recognize 2. To enable relaying, serving and reading agents to recognize
articles from origins which they might wish to reject, divert, or articles from origins which they might wish to reject, divert, or
otherwise handle specially, for reasons of site policy. otherwise handle specially, for reasons of site policy.
News Article Format April 2003
3. To enable the timely identification of spews of articles arising 3. To enable the timely identification of spews of articles arising
from a common origin. from a common origin.
An injecting agent MUST NOT include any Injector-Info-parameter An injecting agent MUST NOT include any Injector-Info-parameter
unless it has positive evidence of its correctness. An injecting unless it has positive evidence of its correctness. An injecting
agent MAY include extension-parameters with x-token attributes which agent MAY also include extension-parameters with x-attributes which
will assist in identifying the origin of the article. will assist in identifying the origin of the article.
NOTE: Administrators of injecting agents can choose which NOTE: Administrators of injecting agents can choose which
selection of the following parameters best enables them to fulfil selection of the following parameters best enables them to fulfil
their responsibilities. Some of these parameters identify the their responsibilities. Some of these parameters identify the
source of the article explicitly whereas others do so indirectly, source of the article explicitly whereas others do so indirectly,
News Article Format February 2003
thus affording more privacy to posters who value their anonymity, thus affording more privacy to posters who value their anonymity,
but also making harder the tracking of malicious disruption of the but also making harder the tracking of malicious disruption of the
network, especially so if the administrators choose not to network, especially so if the administrators choose not to
cooperate. There is thus a balance to be struck between the needs cooperate. There is thus a balance to be struck between the needs
of privacy on the one hand and the good order of Usenet on the of privacy on the one hand and the good order of Usenet on the
other, and administrators need to be aware of this when other, and administrators need to be aware of this when
formulating their policies. formulating their policies.
6.19.1.1. The posting-host-parameter 6.19.1.1. The posting-host-parameter
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6.19.1.3. The posting-sender-parameter 6.19.1.3. The posting-sender-parameter
This parameter identifies the mailbox of the verified sender of the This parameter identifies the mailbox of the verified sender of the
article (alternatively, it uses the token "verified" to indicate that article (alternatively, it uses the token "verified" to indicate that
at least any addr-spec in the Sender-header of the article, or in the at least any addr-spec in the Sender-header of the article, or in the
From-header if the Sender-header is absent, is correct). From-header if the Sender-header is absent, is correct).
NOTE: An injecting agent is unlikely to be able to make use of NOTE: An injecting agent is unlikely to be able to make use of
this parameter except in cases where it is running on a machine this parameter except in cases where it is running on a machine
which is aware of the user-space in which the posting agent is which is aware of the user-space in which the posting agent is
News Article Format April 2003
operating. This parameter should be used in preference to a operating. This parameter should be used in preference to a
posting-account-parameter in such situations. posting-account-parameter in such situations.
6.19.1.4. The posting-logging-parameter 6.19.1.4. The posting-logging-parameter
This parameter contains information (typically a session number or This parameter contains information (typically a session number or
other non-persistent means of identifying a posting account) which other non-persistent means of identifying a posting account) which
will enable the true origin of the article to be determined by will enable the true origin of the article to be determined by
reference to logging information kept by the injecting agent. reference to logging information kept by the injecting agent.
News Article Format February 2003
6.19.1.5. The posting-date-parameter 6.19.1.5. The posting-date-parameter
This parameter identifies the time at which the article was injected This parameter identifies the time at which the article was injected
(as distinct from the Date-header, which indicates when it was (as distinct from the Date-header, which indicates when it was
written). written).
6.19.2. Example 6.19.2. Example
Injector-Info: news2.isp.net; posting-host=modem-15.pop.isp.net; Injector-Info: news2.isp.net; posting-host=modem-15.pop.isp.net;
posting-account=client0002623; logging-data=2427; posting-account=client0002623; logging-data=2427;
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behaviour of the poster of the article; it SHOULD NOT be used for behaviour of the poster of the article; it SHOULD NOT be used for
matters concerning propagation, protocol problems, etc. which should matters concerning propagation, protocol problems, etc. which should
be addressed to "usenet@" or "news@" the path-identity which was be addressed to "usenet@" or "news@" the path-identity which was
prepended to the Path-header by the injecting agent, in accordance prepended to the Path-header by the injecting agent, in accordance
with section 5.6.2. In the absence of this header, complaints with section 5.6.2. In the absence of this header, complaints
concerning a poster's behaviour MAY be addressed to "abuse@" that concerning a poster's behaviour MAY be addressed to "abuse@" that
path-identity (although section 5.6.2 provides no obligation for that path-identity (although section 5.6.2 provides no obligation for that
address to be mailable at an injecting agent that is not provided for address to be mailable at an injecting agent that is not provided for
the use of the general public). the use of the general public).
News Article Format April 2003
6.21. MIME headers 6.21. MIME headers
6.21.1. Syntax 6.21.1. Syntax
The following headers may be used within articles conforming to this The following headers may be used within articles conforming to this
standard. standard.
MIME-Version: [RFC 2045] MIME-Version: [RFC 2045]
Content-Type: [RFC 2045],[RFC 2046] Content-Type: [RFC 2045],[RFC 2046]
Content-Transfer-Encoding: [RFC 2045] Content-Transfer-Encoding: [RFC 2045]
Content-ID: [RFC 2045] Content-ID: [RFC 2045]
News Article Format February 2003
Content-Description: [RFC 2045] Content-Description: [RFC 2045]
Content-Disposition: [RFC 2183] Content-Disposition: [RFC 2183]
Content-Location: [RFC 2557] Content-Location: [RFC 2557]
Content-Language: [RFC 3282] Content-Language: [RFC 3282]
Content-MD5: [RFC 1864] Content-MD5: [RFC 1864]
The RFCs listed are deemed to be incorporated into this standard to The RFCs listed are deemed to be incorporated into this standard to
the extent necessary to facilitate their usage within Netnews, the extent necessary to facilitate their usage within Netnews,
subject to the revised syntax of parameter given in this standard subject to curtailment of that usage as described in the following
(which permits UTF-xtra-chars to appear within quoted-strings used as sections. Moreover, extensions to those standards registered in
values), and subject to curtailment of that usage as described in the accordance with [RFC 2048] are also available for use within Netnews,
following sections. Moreover, extensions to those standards as indeed is any other header in the Content-* series which has a
registered in accordance with [RFC 2048] are also available for use sensible interpretation within Netnews.
within Netnews, as indeed is any other header in the Content-* series
which has a sensible interpretation within Netnews.
Insofar as the syntax for these headers, as given in those RFCs does Insofar as the syntax for these headers, as given in those RFCs does
not specify precisely where whitespace and comments may occur not specify precisely where whitespace and comments may occur
(whether in the form of WSP, FWS or CFWS), the usage defined in this (whether in the form of WSP, FWS or CFWS), the usage defined in this
standard, and failing that in [RFC 2822], and failing that in [RFC standard, and failing that in [RFC 2822], and failing that in [RFC
822] MUST be followed. In particular, there MUST NOT be any WSP 822] MUST be followed. In particular, there MUST NOT be any WSP
between a header-name and the following colon and there MUST be a SP between a header-name and the following colon and there MUST be a SP
following that colon. following that colon.
6.21.2. Content-Type 6.21.2. Content-Type
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to use them unless established policy or custom in the particular to use them unless established policy or custom in the particular
hierarchies or groups involved so allows. Moreover, even in those hierarchies or groups involved so allows. Moreover, even in those
cases, for the benefit of readers who see it only in its transmitted cases, for the benefit of readers who see it only in its transmitted
form, the material SHOULD be "pretty-printed" (for example by form, the material SHOULD be "pretty-printed" (for example by
restricting its line length as above and by keeping sequences which restricting its line length as above and by keeping sequences which
control its layout or style separate from the meaningful text). control its layout or style separate from the meaningful text).
In the same way, Content-Types requiring special processing for their In the same way, Content-Types requiring special processing for their
display, such as "application", "image", "audio", "video" and display, such as "application", "image", "audio", "video" and
"multipart/related" are discouraged except in groups specifically "multipart/related" are discouraged except in groups specifically
News Article Format April 2003
intended (by policy or custom) to include them. Exceptionally, those intended (by policy or custom) to include them. Exceptionally, those
application types defined in [RFC 1847] and [RFC 3156] for use within application types defined in [RFC 1847] and [RFC 3156] for use within
"multipart/signed" articles, and the type "application/pgp-keys" (or "multipart/signed" articles, and the type "application/pgp-keys" (or
other similar types containing digital certificates) may be used other similar types containing digital certificates) may be used
freely. freely.
Reading agents SHOULD NOT, unless explicitly configured otherwise, Reading agents SHOULD NOT, unless explicitly configured otherwise,
act automatically on Application types which could change the state act automatically on Application types which could change the state
of that agent (e.g. by writing or modifying files), except in the of that agent (e.g. by writing or modifying files), except in the
News Article Format February 2003
case of those prescribed for use in control messages (7.2.1.2 and case of those prescribed for use in control messages (7.2.1.2 and
7.2.4.1). 7.2.4.1).
6.21.2.1. Message/partial 6.21.2.1. Message/partial
The Content-Type "message/partial" MAY be used to split a long news The Content-Type "message/partial" MAY be used to split a long news
article into several smaller ones. article into several smaller ones.
NOTE: This Content-Type is not recommended for textual articles NOTE: This Content-Type is not recommended for textual articles
because the Content-Type, and in particular the charset, of the because the Content-Type, and in particular the charset, of the
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6.21.2.2. Message/rfc822 6.21.2.2. Message/rfc822
The Content-Type "message/rfc822" should be used for the The Content-Type "message/rfc822" should be used for the
encapsulation (whether as part of another news article or, more encapsulation (whether as part of another news article or, more
usually, as part of an email message) of complete news articles which usually, as part of an email message) of complete news articles which
have already been posted to Netnews and which are for the information have already been posted to Netnews and which are for the information
of the recipient, and do not constitute a request to repost them of the recipient, and do not constitute a request to repost them
(refer to 6.21.6.2 for the now obsolete "message/news" formerly (refer to 6.21.6.2 for the now obsolete "message/news" formerly
intended for this purpose). intended for this purpose).
News Article Format April 2003
In the case where such an encapsulated news article is to be In the case where such an encapsulated news article is to be
transported by email and it has Content-Transfer-Encoding "8bit", the transported by email and it has Content-Transfer-Encoding "8bit", the
Content-Transfer-Encoding may need to be changed, although there Content-Transfer-Encoding may need to be changed, although there
should be no problems if the email transport supports 8BITMIME [RFC should be no problems if the email transport supports 8BITMIME [RFC
2821]. If, however, its headers contain any UTF8-xtra-chars (2.4.2), 2821].
the requirements on transformations given in section 8.8.1.1 MUST be
followed. It may be necessary to reverse these changes at the far end
if certain forms of digital signature have been employed in the
article.
News Article Format February 2003
6.21.2.3. Message/external-body 6.21.2.3. Message/external-body
The Content-Type "message/external-body" could be appropriate for The Content-Type "message/external-body" could be appropriate for
texts which it would be uneconomic (in view of the likely readership) texts which it would be uneconomic (in view of the likely readership)
to distribute to the entire network. to distribute to the entire network.
6.21.2.4. Multipart types 6.21.2.4. Multipart types
The Content-Types "multipart/mixed", "multipart/parallel" and The Content-Types "multipart/mixed", "multipart/parallel" and
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1. The content type implies that the content is (or may be) "8bit- 1. The content type implies that the content is (or may be) "8bit-
unsafe"; i.e. it may contain octets equivalent to the US-ASCII unsafe"; i.e. it may contain octets equivalent to the US-ASCII
characters CR or LF (other than in the combination CRLF) or NUL. characters CR or LF (other than in the combination CRLF) or NUL.
In that case one of the Content-Transfer-Encodings "base64" or In that case one of the Content-Transfer-Encodings "base64" or
"quoted-printable" MUST be used, and reading agents MUST be able "quoted-printable" MUST be used, and reading agents MUST be able
to handle both of them. Encoding "binary" MUST NOT be used (except to handle both of them. Encoding "binary" MUST NOT be used (except
in cooperating subnets with alternative transport arrangements) in cooperating subnets with alternative transport arrangements)
because this standard does not mandate a transport mechanism that because this standard does not mandate a transport mechanism that
could support it. could support it.
News Article Format April 2003
NOTE: If a future extension to the MIME standards were to NOTE: If a future extension to the MIME standards were to
provide a more compact encoding of binary suited to transport provide a more compact encoding of binary suited to transport
over an 8bit channel, it could be considered as an alternative over an 8bit channel, it could be considered as an alternative
to base64 once it had gained widespread acceptance. to base64 once it had gained widespread acceptance.
News Article Format February 2003
2. It is often the case that "application" Content-Types are textual 2. It is often the case that "application" Content-Types are textual
in nature, and intelligible to humans as well as to machines, and in nature, and intelligible to humans as well as to machines, and
where this state can be recognized by the posting agent (either where this state can be recognized by the posting agent (either
through knowledge of the particular application type or by through knowledge of the particular application type or by
testing) the material SHOULD NOT be treated as 8bit-unsafe; this testing) the material SHOULD NOT be treated as 8bit-unsafe; this
has the added benefit, where the posting agent uses other than has the added benefit, where the posting agent uses other than
CRLF for line endings internally, of automatically ensuring that CRLF for line endings internally, of automatically ensuring that
line endings are processed correctly during transport. line endings are processed correctly during transport.
If, on the other hand, the posting agent recognizes that the If, on the other hand, the posting agent recognizes that the
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between OpenPGP [RFC 2440] and earlier versions of PGP may render between OpenPGP [RFC 2440] and earlier versions of PGP may render
signatures written with the one unverifiable by the other; and, signatures written with the one unverifiable by the other; and,
moreover, Usenet articles are very likely to include trailing moreover, Usenet articles are very likely to include trailing
whitespace in the form of a personal signature (4.3.2). whitespace in the form of a personal signature (4.3.2).
5. The Content-Type message/partial [RFC 2046] is required to use 5. The Content-Type message/partial [RFC 2046] is required to use
encoding "7bit" (the encapsulated complete message may itself use encoding "7bit" (the encapsulated complete message may itself use
encoding "quoted-printable" or "base64", but that information is encoding "quoted-printable" or "base64", but that information is
only conveyed along with the first of the partial parts). only conveyed along with the first of the partial parts).
News Article Format April 2003
NOTE: Although there would actually be no problem using encoding NOTE: Although there would actually be no problem using encoding
"8bit" in a pure Netnews (as opposed to Email) environment, this "8bit" in a pure Netnews (as opposed to Email) environment, this
standard discourages (see 6.21.2.1) the use of "message/partial" standard discourages (see 6.21.2.1) the use of "message/partial"
except for binary material, which will likely be encoded to pass except for binary material, which will likely be encoded to pass
through "7bit" in any case. through "7bit" in any case.
News Article Format February 2003
Injecting and relaying agents MUST NOT change the encoding of Injecting and relaying agents MUST NOT change the encoding of
articles passed to them. Gateways SHOULD NOT change the encoding articles passed to them. Gateways SHOULD NOT change the encoding
unless absolutely necessary. unless absolutely necessary.
6.21.4. Character Sets 6.21.4. Character Sets
In principle, any character set may be specified in the "charset=" In principle, any character set may be specified in the "charset="
parameter of a content type. However, only those character sets (and parameter of a content type. However, only those character sets (and
the corresponding parts of UTF-8) should be used which are the corresponding parts of character sets based on [UNICODE 3.2] such
appropriate for the customary language(s) of the hierarchy or UTF-8) should be used which are appropriate for the customary
newsgroup concerned (whose readers could be expected to possess language(s) of the hierarchy or newsgroup concerned (whose readers
agents capable of displaying them). could be expected to possess agents capable of displaying them).
6.21.5. Content Disposition 6.21.5. Content Disposition
Reading agents Ought to honour any Content-Disposition-header that is Reading agents Ought to honour any Content-Disposition-header that is
provided (in particular, they Ought to display any part of a provided (in particular, they Ought to display any part of a
multipart for which the disposition is "inline", possibly multipart for which the disposition is "inline", possibly
distinguished from adjacent parts by some suitable separator). In the distinguished from adjacent parts by some suitable separator). In the
absence of such a header, the body of an article or any part of a absence of such a header, the body of an article or any part of a
multipart with Content-Type "text" Ought to be displayed inline. multipart with Content-Type "text" Ought to be displayed inline.
Followup agents which quote parts of a precursor (see 4.3.2) Ought Followup agents which quote parts of a precursor (see 4.3.2) Ought
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the recipient should then inject them into Netnews. This Application the recipient should then inject them into Netnews. This Application
type provides one of the methods for mailing articles to moderators type provides one of the methods for mailing articles to moderators
(see 8.2.2) and it is also the preferred method when sending to an (see 8.2.2) and it is also the preferred method when sending to an
email-to-news gateway (see 8.8.2). email-to-news gateway (see 8.8.2).
NOTE: The benefit of such encapsulation is that it removes NOTE: The benefit of such encapsulation is that it removes
possible conflict between news and email headers and it provides possible conflict between news and email headers and it provides
a convenient way of "tunnelling" a news article through a a convenient way of "tunnelling" a news article through a
transport medium that does not support 8bit characters. transport medium that does not support 8bit characters.
News Article Format April 2003
The MIME content type definition of "application/news-transmission" The MIME content type definition of "application/news-transmission"
is: is:
MIME type name: application MIME type name: application
MIME subtype name: news-transmission MIME subtype name: news-transmission
Required parameters: none Required parameters: none
Optional parameters: usage=moderate Optional parameters: usage=moderate
News Article Format February 2003
usage=inject usage=inject
usage=relay usage=relay
Encoding considerations: A transfer-encoding (such as Quoted- Encoding considerations: A transfer-encoding (such as Quoted-
Printable or Base64) different from that of Printable or Base64) different from that of
the article transmitted MAY be supplied the article transmitted MAY be supplied
(perhaps en route) to ensure correct (perhaps en route) to ensure correct
transmission over some 7bit transport transmission over some 7bit transport
medium. medium.
Security considerations: A news article may be a "control message", Security considerations: A news article may be a "control message",
which could have effects on the recipient which could have effects on the recipient
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Thus a batch is a sequence of articles, each prefixed by a header Thus a batch is a sequence of articles, each prefixed by a header
line that includes its size. The article-size is a decimal count of line that includes its size. The article-size is a decimal count of
the octets in the article, counting each CRLF as one octet regardless the octets in the article, counting each CRLF as one octet regardless
of how it is actually represented. of how it is actually represented.
NOTE: Despite the similarity of this format to an executable NOTE: Despite the similarity of this format to an executable
UNIX script, it is EXTREMELY unwise to feed such a batch into a UNIX script, it is EXTREMELY unwise to feed such a batch into a
command interpreter in anticipation of it running a command command interpreter in anticipation of it running a command
named "rnews"; the security implications of so doing would be named "rnews"; the security implications of so doing would be
News Article Format April 2003
disastrous. disastrous.
6.21.6.2. Message/news obsoleted 6.21.6.2. Message/news obsoleted
The Content-Type "message/news", as previously registered with IANA, The Content-Type "message/news", as previously registered with IANA,
is hereby declared obsolete. It was never widely implemented, and its is hereby declared obsolete. It was never widely implemented, and its
default treatment as "application/octet-stream" by agents that did default treatment as "application/octet-stream" by agents that did
News Article Format February 2003
not recognize it was counter productive. The Content-Type not recognize it was counter productive. The Content-Type
"message/rfc822" SHOULD be used in its place, as already described "message/rfc822" SHOULD be used in its place, as already described
above. above.
6.22. Obsolete Headers 6.22. Obsolete Headers
Persons writing new agents SHOULD ignore any former meanings of the Persons writing new agents SHOULD ignore any former meanings of the
following headers: following headers:
Also-Control Also-Control
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steps as are reasonably practicable to validate their authenticity steps as are reasonably practicable to validate their authenticity
(see, for example, section 7.1 below). (see, for example, section 7.1 below).
Relaying Agents MUST propagate even control messages that they do not Relaying Agents MUST propagate even control messages that they do not
recognize. recognize.
In the following sections, each type of control message is defined In the following sections, each type of control message is defined
syntactically by defining its verb, its arguments, and possibly its syntactically by defining its verb, its arguments, and possibly its
body. body.
News Article Format April 2003
7.1. Digital Signature of Headers 7.1. Digital Signature of Headers
It is most desirable that group control messages (7.2) in particular It is most desirable that group control messages (7.2) in particular
be authenticated by incorporating them within some digital signature be authenticated by incorporating them within some digital signature
scheme that encompasses other headers closely associated with them scheme that encompasses other headers closely associated with them
(including at least the Approved-, Message-ID- and Date-headers). At (including at least the Approved-, Message-ID- and Date-headers). At
News Article Format February 2003
the time of writing, this is usually done by means of a protocol the time of writing, this is usually done by means of a protocol
known as "PGPverify" ([PGPVERIFY]), and continued usage of this is known as "PGPverify" ([PGPVERIFY]), and continued usage of this is
encouraged at least as an interim measure. encouraged at least as an interim measure.
However, PGPverify is not considered suitable for standardization in However, PGPverify is not considered suitable for standardization in
its present form, for various technical reasons. It is therefore its present form, for various technical reasons. It is therefore
expected that an early extension to this standard will provide a expected that an early extension to this standard will provide a
robust and general purpose digital authentication mechanism with robust and general purpose digital authentication mechanism with
applicability to all situations requiring protection against applicability to all situations requiring protection against
malicious use of, or interference with, headers. That extension malicious use of, or interference with, headers. That extension
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those subnets. those subnets.
NOTE: Specifically, some alternative flags such as "y" and "m", NOTE: Specifically, some alternative flags such as "y" and "m",
which are sent and recognized by some current software, are NOT which are sent and recognized by some current software, are NOT
part of this standard. Moreover, some existing implementations part of this standard. Moreover, some existing implementations
treat any flag other than "moderated" as indicating an treat any flag other than "moderated" as indicating an
unmoderated newsgroup. Both of these usages are contrary to this unmoderated newsgroup. Both of these usages are contrary to this
standard and control messages with such non-standard flags standard and control messages with such non-standard flags
should be ignored. should be ignored.
News Article Format April 2003
The message body comprises or includes an "application/news- The message body comprises or includes an "application/news-
groupinfo" (7.2.1.2) part containing machine- and human-readable groupinfo" (7.2.1.2) part containing machine- and human-readable
information about the group. information about the group.
News Article Format February 2003 The newsgroup-name Ought to conform to whatever policies have been
established by the administrative agency, if any, for that hierarchy.
It is REQUIRED that the newsgroup-name conforms to all requirements Serving agents SHOULD, insofar as they are conveniently able to
set out in section 5.5. This includes the restrictions as to the detect them, reject all newgroup messages not meeting those
permitted characters, and the requirement that they be invariant requirements.
under NFKC normalization. It is essential that those who issue
newgroup messages are aware of their responsibility to enforce this
requirement, since some of those conditions are hard to enforce
mechanically.
Additionally, the newsgroup-name Ought to conform to whatever
policies have been established by the administrative agency, if any,
for that hierarchy. Serving agents SHOULD, insofar as they are
conveniently able to detect them, reject all newgroup messages not
meeting those requirements.
The newgroup command is also used to update the newsgroups-line or The newgroup command is also used to update the newsgroups-line or
the moderation status of a group. the moderation status of a group.
7.2.1.1. The Body of the 'newgroup' Control Message 7.2.1.1. The Body of the 'newgroup' Control Message
The body of the newgroup message contains the following subparts, The body of the newgroup message contains the following subparts,
preferably in the order shown: preferably in the order shown:
1. An "application/news-groupinfo" part (7.2.1.2) containing the name 1. An "application/news-groupinfo" part (7.2.1.2) containing the name
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NOTE: The presence of the newsgroups-tag "For your newsgroups NOTE: The presence of the newsgroups-tag "For your newsgroups
file:" is intended to make the whole newgroup message compatible file:" is intended to make the whole newgroup message compatible
with current practice as described in [Son-of-1036]. with current practice as described in [Son-of-1036].
The MIME content type definition of "application/news-groupinfo" is: The MIME content type definition of "application/news-groupinfo" is:
MIME type name: application MIME type name: application
MIME subtype name: news-groupinfo MIME subtype name: news-groupinfo
Required parameters: none Required parameters: none
Disposition: by default, inline Disposition: by default, inline
News Article Format February 2003
Encoding considerations: "7bit" or "8bit" is sufficient and MUST be Encoding considerations: "7bit" or "8bit" is sufficient and MUST be
used to maintain compatibility. used to maintain compatibility.
Security considerations: this type MUST NOT be used except as part Security considerations: this type MUST NOT be used except as part
of a control message for the creation or of a control message for the creation or
News Article Format April 2003
modification of a Netnews newsgroup modification of a Netnews newsgroup
Published specification: [USEFOR] Published specification: [USEFOR]
The content of the "application/news-groupinfo" body part is defined The content of the "application/news-groupinfo" body part is defined
as: as:
groupinfo-body = [ newsgroups-tag CRLF ] groupinfo-body = [ newsgroups-tag CRLF ]
newsgroups-line CRLF newsgroups-line CRLF
newsgroups-tag = %x46.6F.72 SP %x79.6F.75.72 SP newsgroups-tag = %x46.6F.72 SP %x79.6F.75.72 SP
%x6E.65.77.73.67.72.6F.75.70.73 SP %x6E.65.77.73.67.72.6F.75.70.73 SP
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; "For your newsgroups file:" ; "For your newsgroups file:"
newsgroups-line = newsgroup-name newsgroups-line = newsgroup-name
[ 1*HTAB newsgroup-description ] [ 1*HTAB newsgroup-description ]
[ 1*WSP moderation-flag ] [ 1*WSP moderation-flag ]
newsgroup-description newsgroup-description
= utext *( *WSP utext ) = utext *( *WSP utext )
moderation-flag = %x28.4D.6F.64.65.72.61.74.65.64.29 moderation-flag = %x28.4D.6F.64.65.72.61.74.65.64.29
; case sensitive "(Moderated)" ; case sensitive "(Moderated)"
The newsgroup-description MUST NOT contain any occurrence of the The newsgroup-description MUST NOT contain any occurrence of the
string "(Moderated)" within it. The whole groupinfo-body is intended string "(Moderated)" within it.
to be interpreted as a text written in the UTF-8 character set.
The "application/news-groupinfo" is used in conjunction with the The "application/news-groupinfo" is used in conjunction with the
"newgroup" (7.2.1) and "mvgroup" (7.2.3) control messages. The "newgroup" (7.2.1) and "mvgroup" (7.2.3) control messages. The
newsgroup-name in the newsgroups-line MUST agree with the newsgroup- newsgroup-name in the newsgroups-line MUST agree with the newsgroup-
name in the "newgroup" or "mvgroup" control message. The Content- name in the "newgroup" or "mvgroup" control message. The Content-
Type "application/news-groupinfo" MUST NOT be used except as a part Type "application/news-groupinfo" MUST NOT be used except as a part
of such control messages. Although optional, the newsgroups-tag of such control messages. Although optional, the newsgroups-tag
SHOULD be included until such time as this standard has been widely SHOULD be included until such time as this standard has been widely
adopted, to ensure compatibility with present practice. adopted, to ensure compatibility with present practice.
Moderated newsgroups MUST be marked by appending the case sensitive Moderated newsgroups MUST be marked by appending the case sensitive
text " (Moderated)" at the end. It is NOT recommended that the text " (Moderated)" at the end. It is NOT recommended that the
moderator's email address be included in the newsgroup-description as moderator's email address be included in the newsgroup-description as
has sometimes been done. has sometimes been done.
NOTE: There is no provision for the use of charsets other than
US-ASCII within a newsgroup-description. Such a facility may be
provided in a future extension to this standard.
[That may seem harsh, but if we make any such provision now, it will
make life more complicated and restrict our freedom when it comes to the
proposed I18N extension. Therefore I resisted the temptation to include
any charset parameter with this Content-Type. Note that this also
applies to the checkgroups message further on.]
Although, in accordance with [RFC 2822] and section 4.5 of this Although, in accordance with [RFC 2822] and section 4.5 of this
standard, a newsgroups-line could have a maximum length of 998 standard, a newsgroups-line could have a maximum length of 998
octets, as a matter of policy a far lower limit, expressed in octets, as a matter of policy a far lower limit, expressed in
characters, Ought to be set. The current convention is to limit its characters, Ought to be set. The current convention is to limit its
length so that the newsgroup-name, the HTAB(s) (interpreted as 8- length so that the newsgroup-name, the HTAB(s) (interpreted as 8-
character tabs that takes one at least to column 24) and the character tabs that takes one at least to column 24) and the
newsgroup-description (excluding any moderation-flag) fit into 79 newsgroup-description (excluding any moderation-flag) fit into 79
News Article Format April 2003
characters. However, this standard does not seek to enforce any such characters. However, this standard does not seek to enforce any such
rule, and reading agents SHOULD therefore enable a newsgroups-line of rule, and reading agents SHOULD therefore enable a newsgroups-line of
any length to be displayed, e.g. by wrapping it as required. any length to be displayed, e.g. by wrapping it as required.
News Article Format February 2003
NOTE: The newsgroups-line is intended to provide a brief
description of the newsgroup, written in the UTF-8 character
set. Since newsgroup-names are required to be expressed in
UTF-8 when they appear in headers, and since [NNTP] requires the
use of UTF-8 when such a description is transmitted by the LIST
NEWSGROUPS command, it would also be convenient for serving
agents that keep a "newsgroups" file to store them in that form,
so as to avoid unnecessary conversions.
[If, at the time of publication of this standard, [NNTP] is still [RFC
977], that NOTE will need to be changed to indicate that "it is expected
that a future extension of [RFC 977] will require ...".]
7.2.1.3. Initial Articles 7.2.1.3. Initial Articles
Some subparts of a "newgroup" or "mvgroup" control message MAY Some subparts of a "newgroup" or "mvgroup" control message MAY
contain an initial set of articles to be posted to the affected contain an initial set of articles to be posted to the affected
newsgroup(s) as soon as it has been created or modified. These parts newsgroup(s) as soon as it has been created or modified. These parts
are identified by having the Content-Type "application/news- are identified by having the Content-Type "application/news-
transmission", possibly with the parameter "usage=inject". The body transmission", possibly with the parameter "usage=inject". The body
of each such part should be a complete proto-article, ready for of each such part should be a complete proto-article, ready for
posting. This feature is intended for the posting of charters, posting. This feature is intended for the posting of charters,
initial FAQs and the like to the newly formed group(s). initial FAQs and the like to the newly formed group(s).
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except as might arise from that possibility, any except as might arise from that possibility, any
"application/news-transmission" within some nested "multipart/*" "application/news-transmission" within some nested "multipart/*"
structure within the proto-article is not to be activated. structure within the proto-article is not to be activated.
7.2.1.4. Example 7.2.1.4. Example
A "newgroup" with its charter: A "newgroup" with its charter:
From: "example.all Administrator" <admin@noc.example> From: "example.all Administrator" <admin@noc.example>
Newsgroups: example.admin.info,example.admin.announce Newsgroups: example.admin.info,example.admin.announce
News Article Format February 2003
Date: 27 Feb 2002 12:50:22 +0200 Date: 27 Feb 2002 12:50:22 +0200
Subject: cmsg newgroup example.admin.info moderated Subject: cmsg newgroup example.admin.info moderated
Approved: admin@noc.example Approved: admin@noc.example
Control: newgroup example.admin.info moderated Control: newgroup example.admin.info moderated
Message-ID: <ng-example.admin.info-20020227@noc.example> Message-ID: <ng-example.admin.info-20020227@noc.example>
MIME-Version: 1.0 MIME-Version: 1.0
News Article Format April 2003
Content-Type: multipart/mixed; boundary="nxtprt" Content-Type: multipart/mixed; boundary="nxtprt"
Content-Transfer-Encoding: 8bit Content-Transfer-Encoding: 8bit
This is a MIME control message. This is a MIME control message.
--nxtprt --nxtprt
Content-Type: application/news-groupinfo Content-Type: application/news-groupinfo
For your newsgroups file: For your newsgroups file:
example.admin.info About the example.* groups (Moderated) example.admin.info About the example.* groups (Moderated)
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it ceases to accept new articles. it ceases to accept new articles.
7.2.2.1. Example 7.2.2.1. Example
Plain "rmgroup": Plain "rmgroup":
From: "example.all Administrator" <admin@noc.example> From: "example.all Administrator" <admin@noc.example>
Newsgroups: example.admin.obsolete, example.admin.announce Newsgroups: example.admin.obsolete, example.admin.announce
Date: 4 Apr 2002 22:04 -0900 (PST) Date: 4 Apr 2002 22:04 -0900 (PST)
Subject: cmsg rmgroup example.admin.obsolete Subject: cmsg rmgroup example.admin.obsolete
News Article Format February 2003
Message-ID: <rm-example.admin.obsolete-20020404@noc.example> Message-ID: <rm-example.admin.obsolete-20020404@noc.example>
Approved: admin@noc.example Approved: admin@noc.example
Control: rmgroup example.admin.obsolete Control: rmgroup example.admin.obsolete
The group example.admin.obsolete is obsolete. Please remove it The group example.admin.obsolete is obsolete. Please remove it
from your system. from your system.
News Article Format April 2003
7.2.3. The 'mvgroup' Control Message 7.2.3. The 'mvgroup' Control Message
control-message =/ Mvgroup-message control-message =/ Mvgroup-message
Mvgroup-message = "mvgroup" Mvgroup-arguments Mvgroup-message = "mvgroup" Mvgroup-arguments
Mvgroup-arguments = CFWS newsgroup-name CFWS newsgroup-name Mvgroup-arguments = CFWS newsgroup-name CFWS newsgroup-name
[ CFWS newgroup-flag ] [ CFWS newgroup-flag ]
The "mvgroup" control message requests that the group specified by The "mvgroup" control message requests that the group specified by
the first (old-)newsgroup-name be moved to that specified by the the first (old-)newsgroup-name be moved to that specified by the
second (new-)newsgroup-name. Thus it is broadly equivalent to a second (new-)newsgroup-name. Thus it is broadly equivalent to a
"newgroup" control message for the second group followed by a "newgroup" control message for the second group followed by a
"rmgroup" control message for the first group. "rmgroup" control message for the first group.
The second (new-)newsgroup-name MUST conform to all requirements The second (new-)newsgroup-name Ought to conform to any established
prescribed for the newsgroup-name of a "newgroup" control message policies of the hierarchy. The message body contains an
(7.2.1) and Ought, similarly, to conform to any established policies "application/news-groupinfo" part (7.2.1.2) containing machine- and
of the hierarchy. The message body contains an "application/news- human-readable information about the new group, and possibly other
groupinfo" part (7.2.1.2) containing machine- and human-readable subparts as for a "newgroup" control message. The information
information about the new group, and possibly other subparts as for a conveyed in the "application/news-groupinfo" body part, notably its
"newgroup" control message. The information conveyed in the newsgroups-line (7.2.1.2), is applied to the new group.
"application/news-groupinfo" body part, notably its newsgroups-line
(7.2.1.2), is applied to the new group.
When this message is received, the new group is created (if it does When this message is received, the new group is created (if it does
not exist already) as for a "newgroup" control message, and MUST in not exist already) as for a "newgroup" control message, and MUST in
any case be made moderated if a newgroup-flag "moderated" is present, any case be made moderated if a newgroup-flag "moderated" is present,
and vice versa. At the same time, arrangements SHOULD be made to and vice versa. At the same time, arrangements SHOULD be made to
remove the old group (as with a "rmgroup" control message), but only remove the old group (as with a "rmgroup" control message), but only
after a suitable overlap period to allow the network to adjust to the after a suitable overlap period to allow the network to adjust to the
new arrangement. new arrangement.
At the same time as a serving agent acts upon this message, all At the same time as a serving agent acts upon this message, all
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NOTE: It is to be expected that different serving agents will NOTE: It is to be expected that different serving agents will
act on this message at different points of time, users of the act on this message at different points of time, users of the
old group will have to become accustomed to the new arrangement, old group will have to become accustomed to the new arrangement,
and followups to already established threads will likely and followups to already established threads will likely
continue under the old group. Therefore, there needs to be an continue under the old group. Therefore, there needs to be an
overlap period during which articles may continue to be accepted overlap period during which articles may continue to be accepted
by relaying and serving agents in either group. This standard by relaying and serving agents in either group. This standard
does not specify any standard period of overlap (though it would does not specify any standard period of overlap (though it would
be expected to be expressed in days rather than in months). The be expected to be expressed in days rather than in months). The
News Article Format February 2003
inhibition of injection of new articles to the old group may inhibition of injection of new articles to the old group may
seem draconian, but it is the surest way to prevent the seem draconian, but it is the surest way to prevent the
changeover from dragging on indefinitely. changeover from dragging on indefinitely.
Since the "mvgroup" control message is newly introduced in this Since the "mvgroup" control message is newly introduced in this
standard and may not be widely implemented initially, it SHOULD be standard and may not be widely implemented initially, it SHOULD be
followed shortly afterwards by a corresponding "newgroup" control followed shortly afterwards by a corresponding "newgroup" control
message; and again, after a reasonable overlap period, it MUST be message; and again, after a reasonable overlap period, it MUST be
followed by a "rmgroup" control message for the old group. followed by a "rmgroup" control message for the old group.
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In order to facilitate a smooth changeover, serving agents MAY In order to facilitate a smooth changeover, serving agents MAY
arrange to service requests for access to the old group by providing arrange to service requests for access to the old group by providing
access to the new group, which would then contain, or appear to access to the new group, which would then contain, or appear to
contain, all articles posted to either group (including, ideally, the contain, all articles posted to either group (including, ideally, the
pre-changeover articles from the old one). Nevertheless, if this pre-changeover articles from the old one). Nevertheless, if this
feature is implemented, the articles themselves, as supplied to feature is implemented, the articles themselves, as supplied to
reading agents, MUST NOT be altered in any way (and, in particular, reading agents, MUST NOT be altered in any way (and, in particular,
their Newsgroups-headers MUST contain exactly those newsgroups their Newsgroups-headers MUST contain exactly those newsgroups
present when they were injected). On the other hand, the Xref-header present when they were injected). On the other hand, the Xref-header
MAY contain entries for either group (or even both). MAY contain entries for either group (or even both).
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7.2.3.1. Example 7.2.3.1. Example
From: "example.all Administrator" <admin@noc.example> From: "example.all Administrator" <admin@noc.example>
Newsgroups: example.oldgroup,example.newgroup,example.admin.announce Newsgroups: example.oldgroup,example.newgroup,example.admin.announce
Date: 30 Apr 2002 22:04 -0500 (EST) Date: 30 Apr 2002 22:04 -0500 (EST)
Subject: cmsg mvgroup example.oldgroup example.newgroup moderated Subject: cmsg mvgroup example.oldgroup example.newgroup moderated
Message-ID: <mvgroup-example.oldgroup-20020430@noc.example> Message-ID: <mvgroup-example.oldgroup-20020430@noc.example>
Approved: admin@noc.example Approved: admin@noc.example
Control: mvgroup example.oldgroup example.newgroup moderated Control: mvgroup example.oldgroup example.newgroup moderated
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MIME-Version: 1.0 MIME-Version: 1.0
Content-Type: multipart/mixed; boundary=nxt Content-Type: multipart/mixed; boundary=nxt
--nxt --nxt
Content-Type: application/news-groupinfo Content-Type: application/news-groupinfo
For your newsgroups file: For your newsgroups file:
example.newgroup The new replacement group (Moderated) example.newgroup The new replacement group (Moderated)
--nxt --nxt
The moderated group example.oldgroup is replaced by The moderated group example.oldgroup is replaced by
example.newgroup. Please update your configuration, and please, example.newgroup. Please update your configuration, and please,
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if possible, arrange to file articles arriving for if possible, arrange to file articles arriving for
example.oldgroup as if they were in example.newgroup. example.oldgroup as if they were in example.newgroup.
--nxt-- --nxt--
7.2.4. The 'checkgroups' Control Message 7.2.4. The 'checkgroups' Control Message
The "checkgroups" control message contains a list of all the valid The "checkgroups" control message contains a list of all the valid
groups in a complete hierarchy. groups in a complete hierarchy.
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and MUST NOT ever decrease. and MUST NOT ever decrease.
NOTE: This was added to circumvent security problems in NOTE: This was added to circumvent security problems in
situations where the Date-header cannot be authenticated. situations where the Date-header cannot be authenticated.
Example: Example:
Control: checkgroups de !de.alt #248 Control: checkgroups de !de.alt #248
which includes the whole of the 'de.*' hierarchy, with the exception which includes the whole of the 'de.*' hierarchy, with the exception
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of its 'de.alt.*' sub-hierarchy. of its 'de.alt.*' sub-hierarchy.
The body of the message has the Content-Type "application/news- The body of the message has the Content-Type "application/news-
checkgroups". It asserts that the newsgroups it lists are the only checkgroups". It asserts that the newsgroups it lists are the only
newsgroups in the specified hierarchies. newsgroups in the specified hierarchies.
NOTE: The checkgroups message is intended to synchronize the NOTE: The checkgroups message is intended to synchronize the
list of newsgroups stored by a serving agent, and their list of newsgroups stored by a serving agent, and their
newsgroup-descriptions, with the lists stored by other serving newsgroup-descriptions, with the lists stored by other serving
agents throughout the network. However, it might be inadvisable agents throughout the network. However, it might be inadvisable
for the serving agent actually to create or delete any for the serving agent actually to create or delete any
newsgroups without first obtaining the approval of its newsgroups without first obtaining the approval of its
administrators for such proposed actions. administrators for such proposed actions.
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7.2.4.1. Application/news-checkgroups 7.2.4.1. Application/news-checkgroups
The "application/news-checkgroups" body part contains a complete list The "application/news-checkgroups" body part contains a complete list
of all the newsgroups in a hierarchy, their newsgroup-descriptions of all the newsgroups in a hierarchy, their newsgroup-descriptions
and their moderation status. and their moderation status.
The MIME content type definition of "application/news-checkgroups" The MIME content type definition of "application/news-checkgroups"
is: is:
MIME type name: application MIME type name: application
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Encoding considerations: "7bit" or "8bit" is sufficient and MUST be Encoding considerations: "7bit" or "8bit" is sufficient and MUST be
used to maintain compatibility. used to maintain compatibility.
Security considerations: this type MUST NOT be used except as part Security considerations: this type MUST NOT be used except as part
of a checkgroups control message of a checkgroups control message
The content of the "application/news-checkgroups" body part is The content of the "application/news-checkgroups" body part is
defined as: defined as:
checkgroups-body = *( valid-group CRLF ) checkgroups-body = *( valid-group CRLF )
valid-group = newsgroups-line ; see 7.2.1.2 valid-group = newsgroups-line ; see 7.2.1.2
The whole checkgroups-body is intended to be interpreted as a text
written in the UTF-8 character set.
The "application/news-checkgroups" content type is used in The "application/news-checkgroups" content type is used in
conjunction with the "checkgroups" control message (7.2.4). conjunction with the "checkgroups" control message (7.2.4).
NOTE: The possibility of removing a complete hierarchy by means NOTE: The possibility of removing a complete hierarchy by means
of an "invalidation" line beginning with a '!' is no longer of an "invalidation" line beginning with a '!' is no longer
provided by this standard. The intent of the feature was widely provided by this standard. The intent of the feature was widely
misunderstood and it was misused more often than it was used misunderstood and it was misused more often than it was used
correctly. The same effect, if required, can now be obtained by correctly. The same effect, if required, can now be obtained by
the use of an appropriate chkscope argument in conjunction with the use of an appropriate chkscope argument in conjunction with
an empty checkgroups-body. an empty checkgroups-body.
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7.3. Cancel 7.3. Cancel
The cancel message requests that a target article be "canceled" i.e. The cancel message requests that a target article be "canceled" i.e.
be withdrawn from circulation or access. A cancel message may be be withdrawn from circulation or access. A cancel message may be
issued in the following circumstances. issued in the following circumstances.
1. The poster of an article (or, more specifically, any entity 1. The poster of an article (or, more specifically, any entity
mentioned in the From-header or the Sender-header, whether or not mentioned in the From-header or the Sender-header, whether or not
that entity was the actual poster) is always entitled to issue a that entity was the actual poster) is always entitled to issue a
cancel message for that article, and serving agents SHOULD honour cancel message for that article, and serving agents SHOULD honour
such requests. Posting agents SHOULD facilitate the issuing of such requests. Posting agents SHOULD facilitate the issuing of
cancel messages by posters fulfilling these criteria. cancel messages by posters fulfilling these criteria.
2. The agent which injected the article onto the network (more 2. The agent which injected the article onto the network (more
specifically, the entity identified by the path-identity in front specifically, the entity identified by the path-identity in front
of the leftmost '%' delimiter in the Path-header (5.6) or in the of the leftmost '%' delimiter in the Path-header (5.6) or in the
Injector-Info-header (6.19) and, where appropriate, the moderator Injector-Info-header (6.19) and, where appropriate, the moderator
(more specifically, any entity mentioned in the Approved-header) (more specifically, any entity mentioned in the Approved-header)
is always entitled to issue a cancel message for that article, and is always entitled to issue a cancel message for that article, and
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serving agents SHOULD honour such requests. serving agents SHOULD honour such requests.
3. Other entities MAY be entitled to issue a cancel message for that 3. Other entities MAY be entitled to issue a cancel message for that
article, in circumstances where established policy for any article, in circumstances where established policy for any
hierarchy or group in the Newsgroup-header, or established custom hierarchy or group in the Newsgroup-header, or established custom
within Usenet, so allows (such policies and customs are not within Usenet, so allows (such policies and customs are not
defined by this standard). Such cancel messages MUST include an defined by this standard). Such cancel messages MUST include an
Approved-header identifying the responsible entity. Serving agents Approved-header identifying the responsible entity. Serving agents
MAY honour such requests, but SHOULD first take steps to verify MAY honour such requests, but SHOULD first take steps to verify
their appropriateness. their appropriateness.
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acceptability of the cancel message cannot be established without it, acceptability of the cancel message cannot be established without it,
activation of the cancel message SHOULD be delayed until the target activation of the cancel message SHOULD be delayed until the target
article has been seen. See also sections 8.3 and 8.4. article has been seen. See also sections 8.3 and 8.4.
NOTE: It is expected that the security extension envisaged in NOTE: It is expected that the security extension envisaged in
section 7.1 will make more detailed provisions for establishing section 7.1 will make more detailed provisions for establishing
whether honouring a particular cancel message is in order. In whether honouring a particular cancel message is in order. In
particular, it is likely that there will be provision for the particular, it is likely that there will be provision for the
digital signature of 3rd party cancels. digital signature of 3rd party cancels.
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NOTE: A cancel submitted by the poster for an article in a NOTE: A cancel submitted by the poster for an article in a
moderated group will be forwarded to the moderator of that moderated group will be forwarded to the moderator of that
group, and it is up to that moderator to act upon it (8.7). group, and it is up to that moderator to act upon it (8.7).
NOTE: The former requirement [RFC 1036] that the From and/or NOTE: The former requirement [RFC 1036] that the From and/or
Sender-headers of the cancel message should match those of the Sender-headers of the cancel message should match those of the
original article has been removed from this standard, since it original article has been removed from this standard, since it
only encouraged cancel issuers to conceal their true identity, only encouraged cancel issuers to conceal their true identity,
and it was not usually checked or enforced by canceling and it was not usually checked or enforced by canceling
software. Therefore, both the From and/or Sender-headers and software. Therefore, both the From and/or Sender-headers and
any Approved-header should now relate to the entity responsible any Approved-header should now relate to the entity responsible
for issuing the cancel message. for issuing the cancel message.
7.4. Ihave, sendme 7.4. Ihave, sendme
The "ihave" and "sendme" control messages implement a crude batched The "ihave" and "sendme" control messages implement a crude batched
predecessor of the NNTP [NNTP] protocol. They are largely obsolete on predecessor of the NNTP [NNTP] protocol. They are largely obsolete on
the Internet, but still see use in conjunction with some transport the Internet, but still see use in conjunction with some transport
protocols such as UUCP, especially for backup feeds that normally are protocols such as UUCP, especially for backup feeds that normally are
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active only when a primary feed path has failed. There is no active only when a primary feed path has failed. There is no
requirement for relaying agents that do not support such transport requirement for relaying agents that do not support such transport
protocols to implement them. protocols to implement them.
NOTE: The ihave and sendme messages defined here have ABSOLUTELY NOTE: The ihave and sendme messages defined here have ABSOLUTELY
NOTHING TO DO WITH NNTP, despite similarities of terminology. NOTHING TO DO WITH NNTP, despite similarities of terminology.
The two messages share the same syntax: The two messages share the same syntax:
control-message =/ Ihave-message control-message =/ Ihave-message
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The ihave message states that the named relaying agent has received The ihave message states that the named relaying agent has received
articles with the specified message identifiers, which may be of articles with the specified message identifiers, which may be of
interest to the relaying agents receiving the ihave message. The interest to the relaying agents receiving the ihave message. The
sendme message requests that the agent receiving it send the articles sendme message requests that the agent receiving it send the articles
having the specified message identifiers to the named relaying agent. having the specified message identifiers to the named relaying agent.
These control messages are normally sent essentially as point-to- These control messages are normally sent essentially as point-to-
point messages, by using newsgroup-names in the Newsgroups-header of point messages, by using newsgroup-names in the Newsgroups-header of
the form "to." followed by one (or possibly more) components in the the form "to." followed by one (or possibly more) components in the
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form of a relayer-name (see section 5.5.1 which forbids "to" as the form of a relayer-name (see section 5.5.1 which forbids "to" as the
first component of a newsgroup-name). The control message SHOULD then first component of a newsgroup-name). The control message SHOULD then
be delivered ONLY to the relaying agent(s) identified by that be delivered ONLY to the relaying agent(s) identified by that
relayer-name, and any relaying agent receiving such a message which relayer-name, and any relaying agent receiving such a message which
includes its own relayer-name MUST NOT propagate it further. Each includes its own relayer-name MUST NOT propagate it further. Each
pair of relaying agent(s) sending and receiving these messages MUST pair of relaying agent(s) sending and receiving these messages MUST
be immediate neighbors, exchanging news directly with each other. be immediate neighbors, exchanging news directly with each other.
Each relaying agent advertises its new arrivals to the other using Each relaying agent advertises its new arrivals to the other using
ihave messages, and each uses sendme messages to request the articles ihave messages, and each uses sendme messages to request the articles
it lacks. it lacks.
To reduce overhead, ihave and sendme messages SHOULD be sent To reduce overhead, ihave and sendme messages SHOULD be sent
relatively infrequently and SHOULD contain reasonable numbers of relatively infrequently and SHOULD contain reasonable numbers of
message IDs. If ihave and sendme are being used to implement a backup message IDs. If ihave and sendme are being used to implement a backup
feed, it may be desirable to insert a delay between reception of an feed, it may be desirable to insert a delay between reception of an
ihave and generation of a sendme, so that a slightly slow primary ihave and generation of a sendme, so that a slightly slow primary
feed will not cause large numbers of articles to be requested feed will not cause large numbers of articles to be requested
unnecessarily via sendme. unnecessarily via sendme.
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7.5. Obsolete control messages. 7.5. Obsolete control messages.
The following control messages are declared obsolete by this The following control messages are declared obsolete by this
standard: standard:
sendsys sendsys
version version
whogets whogets
senduuname senduuname
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various combinations of the injecting, relaying and serving various combinations of the injecting, relaying and serving
functions. Its duties are then the union of the various duties functions. Its duties are then the union of the various duties
concerned. concerned.
8.1. General principles to be followed 8.1. General principles to be followed
There are two important principles that news implementors (and There are two important principles that news implementors (and
administrators) need to keep in mind. The first is the well-known administrators) need to keep in mind. The first is the well-known
Internet Robustness Principle: Internet Robustness Principle:
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Be liberal in what you accept, and conservative in what you Be liberal in what you accept, and conservative in what you
send. send.
However, in the case of news there is an even more important However, in the case of news there is an even more important
principle, derived from a much older code of practice, the principle, derived from a much older code of practice, the
Hippocratic Oath (we may thus call this the Hippocratic Principle): Hippocratic Oath (we may thus call this the Hippocratic Principle):
First, do no harm. First, do no harm.
It is VITAL to realize that decisions which might be merely It is VITAL to realize that decisions which might be merely
suboptimal in a smaller context can become devastating mistakes when suboptimal in a smaller context can become devastating mistakes when
amplified by the actions of thousands of hosts within a few minutes. amplified by the actions of thousands of hosts within a few minutes.
In the case of gateways, the primary corollary to this is: In the case of gateways, the primary corollary to this is:
Cause no loops. Cause no loops.
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8.2. Duties of an Injecting Agent 8.2. Duties of an Injecting Agent
An Injecting Agent is responsible for taking a proto-article from a An Injecting Agent is responsible for taking a proto-article from a
posting agent and either forwarding it to a moderator or injecting it posting agent and either forwarding it to a moderator or injecting it
into the relaying system for access by readers. into the relaying system for access by readers.
As such, an injecting agent is considered responsible for ensuring As such, an injecting agent is considered responsible for ensuring
that any article it injects conforms with the rules of this standard that any article it injects conforms with the rules of this standard
and the policies of any newsgroups or hierarchies that the article is and the policies of any newsgroups or hierarchies that the article is
posted to. It is also expected to bear some responsibility towards posted to. It is also expected to bear some responsibility towards
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Message-Id-header, Date-header, Path-header (and even From-header if Message-Id-header, Date-header, Path-header (and even From-header if
the particular injecting agent can derive that information from other the particular injecting agent can derive that information from other
sources). These headers MUST NOT contain invalid values; they MUST sources). These headers MUST NOT contain invalid values; they MUST
either be correct or not present at all. either be correct or not present at all.
A proto-article SHOULD NOT contain the '%' path-delimiter in any A proto-article SHOULD NOT contain the '%' path-delimiter in any
Path-header, except in the rare cases where an article gets injected Path-header, except in the rare cases where an article gets injected
twice. It MAY contain path-identities with other path-delimiters in twice. It MAY contain path-identities with other path-delimiters in
the pre-injection portion of the Path-header (5.6.3). the pre-injection portion of the Path-header (5.6.3).
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8.2.2. Procedure to be followed by Injecting Agents 8.2.2. Procedure to be followed by Injecting Agents
A injecting agent receives proto-articles from posting and followup A injecting agent receives proto-articles from posting and followup
agents. It verifies them, adds headers where required and then either agents. It verifies them, adds headers where required and then either
forwards them to a moderator or injects them by passing them to forwards them to a moderator or injects them by passing them to
serving or relaying agents. serving or relaying agents.
If an injecting agent receives an otherwise valid article that has If an injecting agent receives an otherwise valid article that has
already been injected it SHOULD either act as if it is a relaying already been injected it SHOULD either act as if it is a relaying
agent or else pass the article on to a relaying agent completely agent or else pass the article on to a relaying agent completely
unaltered. Exceptionally, it MAY reinject the article, perhaps as a unaltered. Exceptionally, it MAY reinject the article, perhaps as a
part of some complex gatewaying process (in which case it will add a part of some complex gatewaying process (in which case it will add a
second '%' path-delimiter to the Path-header). It MUST NOT forward second '%' path-delimiter to the Path-header). It MUST NOT forward
an already injected article to a moderator. an already injected article to a moderator.
An injecting agent processes articles as follows: An injecting agent processes articles as follows:
1. It MUST remove any Injector-Info- or Complaints-To-header already 1. It MUST remove any Injector-Info- or Complaints-To-header already
present (though it might be useful to copy them to suitable X- present (though it might be useful to copy them to suitable X-
headers). It SHOULD likewise remove any NNTP-Posting-Host or other headers). It SHOULD likewise remove any NNTP-Posting-Host or other
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undocumented tracing header. undocumented tracing header.
2. It SHOULD verify that the article is from a trusted source. 2. It SHOULD verify that the article is from a trusted source.
However, it MAY allow articles in which headers contain "forged" However, it MAY allow articles in which headers contain "forged"
email addresses, that is, addresses which are not valid for the email addresses, that is, addresses which are not valid for the
known and trusted source, especially if they end in ".invalid". known and trusted source, especially if they end in ".invalid".
3. It MUST reject any article whose Date-header is more than 24 hours 3. It MUST reject any article whose Date-header is more than 24 hours
into the past or into the future (cf. 5.1). into the past or into the future (cf. 5.1).
4. It MUST reject any article that does not have the correct 4. It MUST reject any article that does not have the correct
mandatory headers for a proto-article (5 and 8.2.1) present, or mandatory headers for a proto-article (5 and 8.2.1) present, or
which contains any header that does not have syntactically legal which contains any header that does not have syntactically legal
contents. In particular, it MUST either reject any article whose contents. It SHOULD reject any article which contains any header
Newsgroups-header or Followup-To-header contains an encoded deprecated for Netnews (4.2.1).
newsgroup-name (5.5.2) or, alternatively, decode those newsgroup-
names and continue (this being a useful service for moderators
using that injecting agent, see 8.7). It SHOULD reject any
article which contains any header deprecated for Netnews (4.2.1).
5. If the article is rejected (for reasons given above, or for other 5. If the article is rejected (for reasons given above, or for other
formatting errors or matters of site policy) the posting agent formatting errors or matters of site policy) the posting agent
SHOULD be informed (such as via an NNTP 44x response code) that SHOULD be informed (such as via an NNTP 44x response code) that
posting has failed and the article MUST NOT then be processed posting has failed and the article MUST NOT then be processed
further. further.
6. The Message-ID and Date-headers (and their contents) MUST be added 6. The Message-ID and Date-headers (and their contents) MUST be added
when not already present. when not already present.
7. A Path-header with a tail-entry (5.6.3) MUST be correctly added if 7. A Path-header with a tail-entry (5.6.3) MUST be correctly added if
not already present (except that it SHOULD NOT be added if the not already present (except that it SHOULD NOT be added if the
article is to be forwarded to a moderator). article is to be forwarded to a moderator).
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8. The path-identity of the injecting agent with a '%' path-delimiter 8. The path-identity of the injecting agent with a '%' path-delimiter
(5.6.2) MUST be prepended to the Path-header; moreover, that (5.6.2) MUST be prepended to the Path-header; moreover, that
path-identity MUST be an FQDN mailable address (5.6.2). path-identity MUST be an FQDN mailable address (5.6.2).
9. An Injector-Info-header (6.19) SHOULD be added, identifying the 9. An Injector-Info-header (6.19) SHOULD be added, identifying the
trusted source of the article, and a suitable Complaints-To-header trusted source of the article, and a suitable Complaints-To-header
(6.20) MAY be added (except that these two headers MUST NOT be (6.20) MAY be added (except that these two headers MUST NOT be
added if the article is to be forwarded to a moderator). added if the article is to be forwarded to a moderator).
10.The injecting agent MUST NOT alter the body of the article in any 10.The injecting agent MUST NOT alter the body of the article in any
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and Complaints-To, which are to be removed as already mentioned. and Complaints-To, which are to be removed as already mentioned.
NOTE: The addition of non-mandatory headers by the injecting NOTE: The addition of non-mandatory headers by the injecting
agent may alter the posting agent's preferred presentation of agent may alter the posting agent's preferred presentation of
information. In particular, adding a Sender-header that exposes information. In particular, adding a Sender-header that exposes
a sender's mailbox has privacy implications; where the main or a sender's mailbox has privacy implications; where the main or
only purpose for doing so is as tracing information, it is only purpose for doing so is as tracing information, it is
preferable to use instead one of the options provided for the preferable to use instead one of the options provided for the
Injector-Info header (6.19.1). Injector-Info header (6.19.1).
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11.If the Newsgroups-header contains no moderated groups, or if it 11.If the Newsgroups-header contains no moderated groups, or if it
contains an Approved-header, the injecting agent forwards the contains an Approved-header, the injecting agent forwards the
article to one or more relaying or serving agents. article to one or more relaying or serving agents.
12.Otherwise, when the Newsgroups-header contains one or more 12.Otherwise, when the Newsgroups-header contains one or more
moderated groups and the article does NOT contain an Approved- moderated groups and the article does NOT contain an Approved-
header, the injecting agent MUST forward it to the moderator of header, the injecting agent MUST forward it to the moderator of
the first (leftmost) moderated group listed in the Newsgroups- the first (leftmost) moderated group listed in the Newsgroups-
header via email. There are two possibilities for doing this: header via email. There are two possibilities for doing this:
(a) The complete article is encapsulated (headers and all) within (a) The complete article is encapsulated (headers and all) within
the email, preferably using the Content-Type the email, preferably using the Content-Type
"application/news-transmission" (6.21.6.1) with any usage "application/news-transmission" (6.21.6.1) with any usage
parameter set to "moderate". Moreover, there SHOULD NOT be parameter set to "moderate". Moreover, there SHOULD NOT be
more than one encapsulated article within the one email. more than one encapsulated article within the one email.
This method has the advantage of removing any possible This method has the advantage of removing any possible
conflict between Netnews and Email headers, or of changes to conflict between Netnews and Email headers, or of changes to
those headers during transport through email (and in those headers during transport through email.
particular, it ensures that any UTF8-xtra-chars within those
headers will pass safely through any email transport even if
it is 8bit-unsafe).
(b) The article is sent as an email as it stands, with the (b) The article is sent as an email as it stands, with the
addition of such extra headers (e.g. a To-header) as are addition of such extra headers (e.g. a To-header) as are
necessary for an email. Since the article is, in effect, necessary for an email.
being gatewayed into Email, if the headers contain any UTF8-
xtra-chars the transformations described in section 8.8.1.1
MUST be applied.
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Although both of these methods have seen use in the past, the Although both of these methods have seen use in the past, the
preponderance of current usage on Usenet has been for method (b) preponderance of current usage on Usenet has been for method (b)
and many moderators are ill-prepared to deal with method (a). and many moderators are ill-prepared to deal with method (a).
Therefore, method (a) SHOULD NOT be used until such time as the Therefore, method (a) SHOULD NOT be used until such time as the
majority of moderators are able to accept it. majority of moderators are able to accept it.
13.This standard does not prescribe how the email address of the 13.This standard does not prescribe how the email address of the
moderator is to be determined, that being a matter of policy to be moderator is to be determined, that being a matter of policy to be
arranged by the agency responsible for the oversight of each arranged by the agency responsible for the oversight of each
hierarchy. Nevertheless, there do exist various agents worldwide hierarchy. Nevertheless, there do exist various agents worldwide
which provide the service of forwarding to moderators, and the which provide the service of forwarding to moderators, and the
address to use with them is obtained as follows: address to use with them is obtained as follows:
(a) Each '.' in the newsgroup-name is replaced with a '-'. (a) Each '.' in the newsgroup-name is replaced with a '-'.
(b) If the newsgroup-name contains any UTF8-xtra-char, it is (b) The result of these operations is used as the local-part of
encoded as described in section 5.5.2.
(c) The result of these operations is used as the local-part of
the mailbox of the agent. For example, articles intended for the mailbox of the agent. For example, articles intended for
"news.announce.important" would be emailed to "news- "news.announce.important" would be emailed to "news-
announce-important@forwardingagent.example". announce-important@forwardingagent.example".
8.3. Duties of a Relaying Agent 8.3. Duties of a Relaying Agent
A Relaying Agent accepts injected articles from injecting and other A Relaying Agent accepts injected articles from injecting and other
relaying agents and passes them on to relaying or serving agents relaying agents and passes them on to relaying or serving agents
according to mutually agreed policy. Relaying agents SHOULD accept according to mutually agreed policy. Relaying agents SHOULD accept
articles ONLY from trusted agents. articles ONLY from trusted agents.
A relaying agent processes articles as follows: A relaying agent processes articles as follows:
News Article Format April 2003
1. It MUST verify the leftmost entry in the Path-header and then 1. It MUST verify the leftmost entry in the Path-header and then
prepend its own path-identity with a '/' path-delimiter, and prepend its own path-identity with a '/' path-delimiter, and
possibly also the verified path-identity of its source with a '?' possibly also the verified path-identity of its source with a '?'
path-delimiter (5.6.2). path-delimiter (5.6.2).
2. It MUST reject any article whose Date-header is stale (see 5.1). 2. It MUST reject any article whose Date-header is stale (see 5.1).
3. It MUST reject any article that does not have the correct 3. It MUST reject any article that does not have the correct
mandatory headers (section 5) present with legal contents. mandatory headers (section 5) present with legal contents.
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not have legal contents. not have legal contents.
5. It SHOULD reject any article that has already been sent to it (a 5. It SHOULD reject any article that has already been sent to it (a
database of message identifiers of recent messages is usually kept database of message identifiers of recent messages is usually kept
and matched against). and matched against).
6. It SHOULD reject any article that matches an already received 6. It SHOULD reject any article that matches an already received
cancel message (or an equivalent Supersedes-header) issued by its cancel message (or an equivalent Supersedes-header) issued by its
poster or by some other trusted entity. poster or by some other trusted entity.
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7. It MAY reject any article without an Approved-header posted to 7. It MAY reject any article without an Approved-header posted to
newsgroups known to be moderated (this practice is strongly newsgroups known to be moderated (this practice is strongly
recommended, but the information necessary to do it may not be recommended, but the information necessary to do it may not be
available to all agents). available to all agents).
8. It then passes articles which match mutually agreed criteria on to 8. It then passes articles which match mutually agreed criteria on to
neighbouring relaying and serving agents. However, it SHOULD NOT neighbouring relaying and serving agents. However, it SHOULD NOT
forward articles to sites whose path-identity is already in the forward articles to sites whose path-identity is already in the
Path-header. Path-header.
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entity has explicitly requested that it be informed of such errors. entity has explicitly requested that it be informed of such errors.
NOTE: In order to prevent overloading, relaying agents should NOTE: In order to prevent overloading, relaying agents should
not routinely query an external entity (such as a DNS-server) in not routinely query an external entity (such as a DNS-server) in
order to verify an article (though a local cache of the required order to verify an article (though a local cache of the required
information might usefully be consulted). information might usefully be consulted).
Relaying agents MUST NOT alter, delete or rearrange any part of an Relaying agents MUST NOT alter, delete or rearrange any part of an
article expect for headers designated as variant (4.2.5.3). article expect for headers designated as variant (4.2.5.3).
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8.4. Duties of a Serving Agent 8.4. Duties of a Serving Agent
A Serving Agent takes an article from a relaying or injecting agent A Serving Agent takes an article from a relaying or injecting agent
and files it in a "news database". It also provides an interface for and files it in a "news database". It also provides an interface for
reading agents to access the news database. This database is normally reading agents to access the news database. This database is normally
indexed by newsgroup with articles in each newsgroup identified by an indexed by newsgroup with articles in each newsgroup identified by an
article-locater (usually in the form of a decimal number - see 6.16). article-locater (usually in the form of a decimal number - see 6.16).
NOTE: Since control messages are often of interest, but should NOTE: Since control messages are often of interest, but should
not be displayed as normal articles in regular newsgroups, it is not be displayed as normal articles in regular newsgroups, it is
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A serving agent processes articles as follows: A serving agent processes articles as follows:
1. It MUST verify the leftmost entry in the Path-header and then 1. It MUST verify the leftmost entry in the Path-header and then
prepend its own path-identity with a '/' path-delimiter, and prepend its own path-identity with a '/' path-delimiter, and
possibly also the verified path-identity of its source with a '?' possibly also the verified path-identity of its source with a '?'
path-delimiter (5.6.2). path-delimiter (5.6.2).
2. It MUST reject any article whose Date-header is stale (see 5.1). 2. It MUST reject any article whose Date-header is stale (see 5.1).
News Article Format February 2003
3. It MUST reject any article that does not have the correct 3. It MUST reject any article that does not have the correct
mandatory headers (section 5) present, or which contains any mandatory headers (section 5) present, or which contains any
header that does not have legal contents. header that does not have legal contents.
4. It SHOULD reject any article that has already been sent to it (a 4. It SHOULD reject any article that has already been sent to it (a
database of message identifiers of recent messages is usually kept database of message identifiers of recent messages is usually kept
and matched against). and matched against).
5. It SHOULD reject any article that matches an already received 5. It SHOULD reject any article that matches an already received
cancel message (or an equivalent Supersedes-header) issued by its cancel message (or an equivalent Supersedes-header) issued by its
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8.5. Duties of a Posting Agent 8.5. Duties of a Posting Agent
A Posting Agent is used to assist the poster in creating a valid A Posting Agent is used to assist the poster in creating a valid
proto-article and forwarding it to an injecting agent. proto-article and forwarding it to an injecting agent.
Postings agents SHOULD ensure that proto-articles they create are Postings agents SHOULD ensure that proto-articles they create are
valid news articles according to this standard and other applicable valid news articles according to this standard and other applicable
policies. policies.
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Posting agents meant for use by ordinary posters SHOULD reject any Posting agents meant for use by ordinary posters SHOULD reject any
attempt to post an article which cancels or Supersedes another attempt to post an article which cancels or Supersedes another
article of which the poster is not the author. article of which the poster is not the author.
8.6. Duties of a Followup Agent 8.6. Duties of a Followup Agent
A Followup Agent is a special case of a posting agent and as such is A Followup Agent is a special case of a posting agent and as such is
bound by all the posting agent's requirements plus additional ones. bound by all the posting agent's requirements plus additional ones.
Followup agents MUST create valid followups, in particular by Followup agents MUST create valid followups, in particular by
providing correctly adjusted forms of those headers described as providing correctly adjusted forms of those headers described as
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Followup agents SHOULD initialize the Newsgroups-header from the Followup agents SHOULD initialize the Newsgroups-header from the
precursor's Followup-To-header, if present, when preparing a precursor's Followup-To-header, if present, when preparing a
followup; however posters MAY then change this before posting if they followup; however posters MAY then change this before posting if they
wish. wish.
Followup agents MUST NOT attempt to send email to any address ending Followup agents MUST NOT attempt to send email to any address ending
in ".invalid". Followup agents SHOULD NOT email copies of the in ".invalid". Followup agents SHOULD NOT email copies of the
followup to the poster of the precursor unless this has been followup to the poster of the precursor unless this has been
explicitly requested by means of a Mail-Copies-To-header (6.8), but explicitly requested by means of a Mail-Copies-To-header (6.8), but
they SHOULD include a Posted-And-Mailed-header (6.9) whenever a copy they SHOULD include a Posted-And-Mailed-header (6.9) whenever a copy
News Article Format February 2003
is so emailed. is so emailed.
8.7. Duties of a Moderator 8.7. Duties of a Moderator
A Moderator receives news articles by email, decides whether to A Moderator receives news articles by email, decides whether to
accept them and, if so, either injects them into the news stream or accept them and, if so, either injects them into the news stream or
forwards them to further moderators. forwards them to further moderators.
Articles will be received by the moderator either encapsulated as an Articles will be received by the moderator either encapsulated as an
object of Content-Type application/news-transmission (or possibly object of Content-Type application/news-transmission (or possibly
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software for whose operation he is then responsible. If the software for whose operation he is then responsible. If the
article is a cancel nessage (7.3) issued by the poster of an article is a cancel nessage (7.3) issued by the poster of an
earlier article, then he Ought to cancel it (in which case there earlier article, then he Ought to cancel it (in which case there
is no more to be done). He MAY modify the article if that is in is no more to be done). He MAY modify the article if that is in
accordance with the applicable moderation policy (and in accordance with the applicable moderation policy (and in
particular he MAY remove redundant headers and add Comments and particular he MAY remove redundant headers and add Comments and
other informational headers). He also needs to be aware if any other informational headers). He also needs to be aware if any
change he makes to the article will invalidate some authentication change he makes to the article will invalidate some authentication
check provided by the poster or by an earlier moderator. check provided by the poster or by an earlier moderator.
News Article Format April 2003
He MAY inform the poster if the article is accepted, and he Ought He MAY inform the poster if the article is accepted, and he Ought
to inform the poster if it is rejected. If it is rejected, then to inform the poster if it is rejected. If it is rejected, then
it normally fails for all the newsgroups for which it was it normally fails for all the newsgroups for which it was
intended. If it is accepted, the moderator proceeds with the intended. If it is accepted, the moderator proceeds with the
following steps. following steps.
2. If the Newsgroups-header contains further moderated newsgroups for 2. If the Newsgroups-header contains further moderated newsgroups for
which approval has not already been given, he adds an indication which approval has not already been given, he adds an indication
(identifying both himself and the name of the group) that he (identifying both himself and the name of the group) that he
approves the article, and then forwards it to the moderator of the approves the article, and then forwards it to the moderator of the
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(a) He emails it to the submission address of the next moderator (a) He emails it to the submission address of the next moderator
(see section 8.2.2 for the proper method of doing this), or (see section 8.2.2 for the proper method of doing this), or
(b) he rotates the newsgroup-names in the Newsgroups-header to (b) he rotates the newsgroup-names in the Newsgroups-header to
the left so that the targeted group is the leftmost moderated the left so that the targeted group is the leftmost moderated
group in that header, and injects it as below (thus causing group in that header, and injects it as below (thus causing
the injecting agent to email it to the correct moderator). the injecting agent to email it to the correct moderator).
However, he MUST first ensure that the article contains no However, he MUST first ensure that the article contains no
Approved-header. Approved-header.
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NOTE: This standard does not prescribe how a moderator's NOTE: This standard does not prescribe how a moderator's
approval is to be indicated (though a future standard may do approval is to be indicated (though a future standard may do
so). Possible methods include adding an Approved header (or a so). Possible methods include adding an Approved header (or a
similar but differently named header if method (b) is being similar but differently named header if method (b) is being
used) listing all the approvals made so far, or adding a used) listing all the approvals made so far, or adding a
separate header for each individual approval (the header X-Auth separate header for each individual approval (the header X-Auth
is sometimes used for this purpose). The approval may also be is sometimes used for this purpose). The approval may also be
confirmed with some form of digital signature (7.1). confirmed with some form of digital signature (7.1).
3. If the Newsgroups-header contains no further unapproved moderated 3. If the Newsgroups-header contains no further unapproved moderated
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within the prerogative of the poster; moreover splitting can lead within the prerogative of the poster; moreover splitting can lead
to fragmentation of threads. to fragmentation of threads.
5. The Date-header SHOULD be retained, except that if it is stale 5. The Date-header SHOULD be retained, except that if it is stale
(5.1) for reasons understood by the moderator (e.g. delays in the (5.1) for reasons understood by the moderator (e.g. delays in the
moderation process) he MAY substitute the current date (but must moderation process) he MAY substitute the current date (but must
then take responsibility for any loops that ensue). The Message- then take responsibility for any loops that ensue). The Message-
ID-header SHOULD also be retained unless it is obviously non- ID-header SHOULD also be retained unless it is obviously non-
compliant with this standard. compliant with this standard.
News Article Format April 2003
NOTE: A message identifier created by a conforming posting or NOTE: A message identifier created by a conforming posting or
injecting agent, or even by a mail user agent conforming to [RFC injecting agent, or even by a mail user agent conforming to [RFC
2822], may reasonably be supposed to be conformant (and will, in 2822], may reasonably be supposed to be conformant (and will, in
any case, be caught by the injecting agent if it is not). any case, be caught by the injecting agent if it is not).
6. Any variant headers (4.2.5.3) MUST be removed, except that a 6. Any variant headers (4.2.5.3) MUST be removed, except that a
Path-header MAY be truncated to only its pre-injection region Path-header MAY be truncated to only its pre-injection region
(5.6.3). Any Injector-Info-header (6.19) or Complaints-To-header (5.6.3). Any Injector-Info-header (6.19) or Complaints-To-header
(6.20) MUST be removed. (6.20) MUST be removed.
7. He then causes the article to be injected, having first decoded 7. He then causes the article to be injected, having first observed
any encoded newsgroup-name (5.5.2), unless his injecting agent all the duties of a posting agent.
offers that service (8.2.2), and having observed all the duties of
a posting agent.
NOTE: This standard does not prescribe how the moderator or NOTE: This standard does not prescribe how the moderator or
moderation policy for each newsgroup is established; rather it moderation policy for each newsgroup is established; rather it
assumes that whatever agencies are responsible for the relevant assumes that whatever agencies are responsible for the relevant
network or hierarchy (1.1) will have made appropriate network or hierarchy (1.1) will have made appropriate
arrangements in that regard. arrangements in that regard.
News Article Format February 2003
8.8. Duties of a Gateway 8.8. Duties of a Gateway
A Gateway transforms an article into the native message format of A Gateway transforms an article into the native message format of
another medium, or translates the messages of another medium into another medium, or translates the messages of another medium into
news articles. Encapsulation of a news article into a message of MIME news articles. Encapsulation of a news article into a message of MIME
type application/news-transmission, or the subsequent undoing of that type application/news-transmission, or the subsequent undoing of that
encapsulation, is not gatewaying, since it involves no transformation encapsulation, is not gatewaying, since it involves no transformation
of the article. of the article.
There are two basic types of gateway, the Outgoing Gateway that There are two basic types of gateway, the Outgoing Gateway that
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below. below.
If bidirectional gatewaying (both an incoming and an outgoing If bidirectional gatewaying (both an incoming and an outgoing
gateway) is being set up between Netnews and some other medium, the gateway) is being set up between Netnews and some other medium, the
incoming and outgoing gateways SHOULD be coordinated to avoid incoming and outgoing gateways SHOULD be coordinated to avoid
reinjection of gated articles. Circular gatewaying (gatewaying a reinjection of gated articles. Circular gatewaying (gatewaying a
message into another medium and then back into Netnews) SHOULD NOT be message into another medium and then back into Netnews) SHOULD NOT be
done; encapsulation of the article SHOULD be used instead where this done; encapsulation of the article SHOULD be used instead where this
is necessary. is necessary.
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A second general principal of gatewaying is that the transformations A second general principal of gatewaying is that the transformations
applied to the message SHOULD be as minimal as possible while still applied to the message SHOULD be as minimal as possible while still
accomplishing the gatewaying. Every change made by a gateway accomplishing the gatewaying. Every change made by a gateway
potentially breaks a property of one of the media or loses potentially breaks a property of one of the media or loses
information, and therefore only those transformations made necessary information, and therefore only those transformations made necessary
by the differences between the media should be applied. by the differences between the media should be applied.
It is worth noting that safe bidirectional gatewaying between a It is worth noting that safe bidirectional gatewaying between a
mailing list and a newsgroup is far easier if the newsgroup is mailing list and a newsgroup is far easier if the newsgroup is
moderated. Posts to the moderated group and submissions to the moderated. Posts to the moderated group and submissions to the
mailing list can then go through a single point that does the mailing list can then go through a single point that does the
necessary gatewaying and then sends the message out to both the necessary gatewaying and then sends the message out to both the
newsgroup and the mailing list at the same time, eliminating most of newsgroup and the mailing list at the same time, eliminating most of
the possibility of loops. Bidirectional gatewaying between a mailing the possibility of loops. Bidirectional gatewaying between a mailing
list and an unmoderated newsgroup, in contrast, is difficult to do list and an unmoderated newsgroup, in contrast, is difficult to do
correctly and is far more fragile. correctly and is far more fragile.
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Newsgroups intended to be bidirectionally gated to a mailing list Newsgroups intended to be bidirectionally gated to a mailing list
SHOULD therefore be moderated where possible, even if the moderator SHOULD therefore be moderated where possible, even if the moderator
is a simple gateway and injecting agent that correctly handles is a simple gateway and injecting agent that correctly handles
crossposting to other moderated groups and otherwise passes all crossposting to other moderated groups and otherwise passes all
traffic. traffic.
8.8.1. Duties of an Outgoing Gateway 8.8.1. Duties of an Outgoing Gateway
From the perspective of Netnews, an outgoing gateway is just a From the perspective of Netnews, an outgoing gateway is just a
special type of reading agent. The exact nature of what the outgoing special type of reading agent. The exact nature of what the outgoing
gateway will need to do to articles depends on the medium to which gateway will need to do to articles depends on the medium to which
the articles are being gated. The operation of the outgoing gateway the articles are being gated. The operation of the outgoing gateway
is only subject to additional constraints in the presence of one or is only subject to additional constraints in the presence of one or
more corresponding incoming gateways back from that medium to more corresponding incoming gateways back from that medium to
Netnews, since this opens the possibility of loops. Netnews, since this opens the possibility of loops.
Where the format of the news article is incompatible with that of the
target medium, it may be necessary to apply transformations (see
8.8.1.1 for the particular case when the target is Email).
In general, the following practices are recommended for all outgoing In general, the following practices are recommended for all outgoing
gateways, regardless of whether there is known to be a related gateways, regardless of whether there is known to be a related
incoming gateway, both as a precautionary measure and as a guideline incoming gateway, both as a precautionary measure and as a guideline
to quality of implementation. to quality of implementation.
1. The message identifier of the news article should be preserved if 1. The message identifier of the news article should be preserved if
at all possible, preferably as or within the corresponding unique at all possible, preferably as or within the corresponding unique
identifier of the other medium, but if not at least as a comment identifier of the other medium, but if not at least as a comment
in the message. This helps greatly with preventing loops. in the message. This helps greatly with preventing loops.
2. The Date of the news article should also be preserved if possible, 2. The Date of the news article should also be preserved if possible,
for similar reasons. for similar reasons.
3. The message should be tagged in some way so as to prevent its 3. The message should be tagged in some way so as to prevent its
reinjection into Netnews. This may be impossible to do without reinjection into Netnews. This may be impossible to do without
knowledge of potential incoming gateways, but it is better to try knowledge of potential incoming gateways, but it is better to try
to provide some indication even if not successful; at the least, a to provide some indication even if not successful; at the least, a
human-readable indication that the article should not be gated human-readable indication that the article should not be gated
back to Netnews can help locate a human problem. back to Netnews can help locate a human problem.
News Article Format April 2003
4. Netnews control messages should not be gated to another medium 4. Netnews control messages should not be gated to another medium
unless they would somehow be meaningful in that medium. unless they would somehow be meaningful in that medium.
8.8.1.1. Gatewaying into email
Although headers containing non-ASCII characters may well be conveyed
intact by many (if not most) current mail transport agents, that
ability is not a requirement of some transport protocols, notably of
SMTP [RFC 2821]. Likewise, although many mail user agents may
currently display (or be configurable to display) such headers
correctly, or at least adequately, messages containing such headers
are not compliant with the current Email standards, notably with [RFC
2822]. Note that non-ASCII body part headers [RFC 2046] (including
non-ASCII headers of a message/rfc822) are equally at variance with
News Article Format February 2003
the current Email standards.
If, at some future time, the Email standards should be updated so as
to allow such headers, it would then become possible to transport
Netnews articles containing them over Email without further ado.
Until such a time, however, if a Netnews article is to be gatewayed
into Email with the intention that it be received and accepted by any
arbitrarily chosen destination, and if it contains any UTF8-xtra-char
in any of its headers or body part headers, then it MUST first be
transformed so as to conform to [RFC 2822] and/or [RFC 2046]. In
particular, articles emailed to moderators (8.2.2) MUST be so
transformed.
NOTE: It is not precluded that a gatewayer who knows, or is able
to control, the capabilities of the particular sites for which
an article is destined and of the transport paths leading to
those sites, may choose to send the article without
transformation, or at least without transformation of any
contained body part headers.
The surest way to transport an article containing non-ASCII headers
through Email is by encapsulation as an application/news-transmission
(6.21.6.1). However this method is not currently available for
sending to moderators for reason explained in section 8.2.2 step 12.
Until this method is considered safe to use, therefore,
transformation of those headers will be necessary. This can be
accomplished in the following steps:
1. If the header is unstructured, or is an experimental header
(4.2.5.1), any word(s) which is delimited by FWS or by the
start/end of the header-content is encoded according to [RFC
2047].
2. If the header is structured, any word(s) which is contained within
a comment and is delimited by FWS or by the "(" or ")" delimiting
that comment is encoded according to [RFC 2047], and likewise any
word(s) which is contained within a phrase and is delimited by FWS
or by the start/end of the header-content.
3. If the header contains a (MIME-style) parameter with a non-ASCII
value, the whole parameter is encoded according to [RFC 2231].
4. If the header is a Newsgroups-header or a Followup-To-header (or
any other header that contains a newsgroup-name), each newsgroup-
name is encoded according to section 5.5.2. Even if it is not
decoded at the far end, it is preferable to display that encoded
form than to display nothing at all. Note, however, that such
encoded newsgroup-names MUST be restored to their canonical form
before reinjection into any Netnews system.
5. Otherwise, if the header is not one defined by this standard or by
any standard known to the gateway (so that it cannot be determined
whether it is unstructured, or otherwise where comments and
phrases occur within it), then it is not possible to encode it
News Article Format February 2003
according to a strict interpretation of [RFC 2047]. In that case,
the suggested treatment is to prepend an "X-" to the header-name,
thus transforming it into an experimental header, and to proceed
as in Step 1. This will ensure that a compliant Email message is
produced and that no information is discarded, but any intended
semantic effect of that header will be lost.
In all cases, there are additional restrictions imposed by [RFC 2047]
regarding the size, placement and contents of encoded-words which
MUST be observed. Moreover, these transformations MUST be applied
both within the header of the article and within any body part
headers (including the headers of any message/rfc822). It is
generally preferable for encodings to use the charset UTF-8, although
it might be wise first to confirm that that is indeed the charset
which had been used (see 4.4.1).
8.8.2. Duties of an Incoming Gateway 8.8.2. Duties of an Incoming Gateway
The incoming gateway has the serious responsibility of ensuring that The incoming gateway has the serious responsibility of ensuring that
all of the requirements of this standard are met by the articles that all of the requirements of this standard are met by the articles that
it forms. In addition to its special duties as a gateway, it bears it forms. In addition to its special duties as a gateway, it bears
all of the duties and responsibilities of an injecting agent as well, all of the duties and responsibilities of an injecting agent as well,
and additionally has the same responsibility of a relaying agent to and additionally has the same responsibility of a relaying agent to
reject articles that it has already gatewayed. reject articles that it has already gatewayed.
An incoming gateway MUST NOT gate the same message twice. It may not An incoming gateway MUST NOT gate the same message twice. It may not
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Incoming gateways MUST NOT pass control messages (articles containing Incoming gateways MUST NOT pass control messages (articles containing
a Control- or Supersedes-header) without removing or renaming that a Control- or Supersedes-header) without removing or renaming that
header. Gateways MAY, however, generate their own cancel messages, header. Gateways MAY, however, generate their own cancel messages,
under the general allowance for injecting agents to cancel their own under the general allowance for injecting agents to cancel their own
messages (7.3). If a gateway receives a message that it can messages (7.3). If a gateway receives a message that it can
determine is a valid equivalent of a cancel message in the medium it determine is a valid equivalent of a cancel message in the medium it
is gatewaying, it SHOULD discard that message without gatewaying it, is gatewaying, it SHOULD discard that message without gatewaying it,
generate a corresponding cancel message of its own, and inject that generate a corresponding cancel message of its own, and inject that
cancel message. cancel message.
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Incoming gateways MUST NOT inject control messages other than Incoming gateways MUST NOT inject control messages other than
cancels. Encapsulation SHOULD be used instead of gatewaying, when cancels. Encapsulation SHOULD be used instead of gatewaying, when
direct posting is not possible or desirable. direct posting is not possible or desirable.
NOTE: It is not unheard of for mail-to-news gateways to be used NOTE: It is not unheard of for mail-to-news gateways to be used
to post control messages, but encapsulation should be used for to post control messages, but encapsulation should be used for
these cases instead. Gateways by their very nature are these cases instead. Gateways by their very nature are
particularly prone to loops. Spews of normal articles are bad particularly prone to loops. Spews of normal articles are bad
enough; spews of control messages with special significance to enough; spews of control messages with special significance to
the news system, possibly resulting in high processing load or the news system, possibly resulting in high processing load or
even email sent for every message received, are catastrophic. It even email sent for every message received, are catastrophic. It
is far preferable to construct a system specifically for posting is far preferable to construct a system specifically for posting
control messages that can do appropriate consistency checks and control messages that can do appropriate consistency checks and
authentication of the originator of the message. authentication of the originator of the message.
News Article Format April 2003
If there is a message identifier that fills a role similar to that of If there is a message identifier that fills a role similar to that of
the Message-ID-header in news, it SHOULD be used in the formation of the Message-ID-header in news, it SHOULD be used in the formation of
the message identifier of the news article, perhaps with the message identifier of the news article, perhaps with
transformations required to meet the uniqueness requirement of transformations required to meet the uniqueness requirement of
Netnews and with the removal of any comments so as to comply with the Netnews and with the removal of any comments so as to comply with the
syntax in section 5.3. Such transformations SHOULD be designed so syntax in section 5.3. Such transformations SHOULD be designed so
that two messages with the same identifier generate the same that two messages with the same identifier generate the same
Message-ID-header. Message-ID-header.
NOTE: Message identifiers play a central role in the prevention NOTE: Message identifiers play a central role in the prevention
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"official" gateway, some other method of generating message "official" gateway, some other method of generating message
identifiers has to be used to avoid collisions. It would identifiers has to be used to avoid collisions. It would
obviously be preferable for there to be only one gateway which obviously be preferable for there to be only one gateway which
crossposts, but this may not be possible to coordinate. crossposts, but this may not be possible to coordinate.
If no date information is available, the gateway MAY supply a Date- If no date information is available, the gateway MAY supply a Date-
header with the gateway's current date. If only partial information header with the gateway's current date. If only partial information
is available (e.g. date but not time), this SHOULD be fleshed out to is available (e.g. date but not time), this SHOULD be fleshed out to
a full Date-header by adding default values rather than discarding a full Date-header by adding default values rather than discarding
this information. Only in very exceptional circumstances should Date this information. Only in very exceptional circumstances should Date
News Article Format February 2003
information be discarded, as it plays an important role in preventing information be discarded, as it plays an important role in preventing
reinjection of old messages. reinjection of old messages.
An incoming gateway MUST add a Sender-header to the news article it An incoming gateway MUST add a Sender-header to the news article it
forms containing the mailbox of the administrator of the gateway. forms containing the mailbox of the administrator of the gateway.