usefor-article-07 May 2002
[TOC] [ Next >]
INTERNET-DRAFT Charles H. Lindsey
Usenet Format Working Group University of Manchester
May 2002
News Article Format
<draft-ietf-usefor-article-07.txt>
Status of this Memo
This document is an Internet-Draft and is in full conformance with
all provisions of Section 10 of RFC 2026.
Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF), its areas, and its working groups. Note that
other groups may also distribute working documents as Internet-
Drafts.
Internet-Drafts are draft documents valid for a maximum of six
months and may be updated, replaced, or obsoleted by other
documents at any time. It is inappropriate to use Internet-Drafts
as reference material or to cite them other than as "work in
progress."
The list of current Internet-Drafts can be accessed at
http://www.ietf.org/ietf/1id-abstracts.txt.
The list of Internet-Draft Shadow Directories can be accessed at
http://www.ietf.org/shadow.html.
Abstract
This Draft is intended as a standards track document, obsoleting
RFC 1036, which itself dates from 1987.
This Standard defines the format of Netnews articles and specifies
the requirements to be met by software which originates, distributes,
stores and displays them.
Since the 1980s, Usenet has grown explosively, and many Internet and
non-Internet sites now participate. In addition, the Netnews
technology is now in widespread use for other purposes.
Backward compatibility has been a major goal of this endeavour, but
where this standard and earlier documents or practices conflict, this
standard should be followed. In most such cases, current practice is
already compatible with these changes.
[The use of the words "this standard" within this document when
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
when it is accepted as an RFC with the status of a proposed or draft
standard.]
[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
explain matters amongst ourselves, or to point out alternatives, or to
assist the RFC Editor.]
[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-
ietf-nntpext-base-*.txt, in the event that such RFC has been accepted at
the time this document is published.]
[Please note that this Draft is now close to Last Call, and the material
included here is unlikely to change in any major way.]
Table of Contents
1. Introduction .................................................. 6
1.1. Basic Concepts ............................................ 6
1.2. Objectives ................................................ 7
1.3. Historical Outline ........................................ 7
1.4. Transport ................................................. 7
2. Definitions, Notations and Conventions ........................ 8
2.1. Definitions ............................................... 8
2.2. Textual Notations ......................................... 9
2.3. Relation To Email and MIME ................................ 10
2.4. Syntax .................................................... 11
2.4.1. Syntax Notation ....................................... 11
2.4.2. Syntax adapted from Email and MIME .................... 11
2.4.3. Syntax copied from other standards .................... 13
2.5. Language .................................................. 14
3. Changes to the existing protocols ............................. 15
3.1. Principal Changes ......................................... 15
3.2. Transitional Arrangements ................................. 15
4. Basic Format .................................................. 17
4.1. Syntax of News Articles ................................... 17
4.2. Headers ................................................... 18
4.2.1. Naming of Headers ..................................... 18
4.2.2. MIME-style Parameters ................................. 19
4.2.3. White Space and Continuations ......................... 20
4.2.4. Comments .............................................. 21
4.2.5. Header Properties ..................................... 22
4.2.5.1. Experimental Headers .............................. 22
4.2.5.2. Inheritable Headers ............................... 22
4.2.5.3. Variant Headers ................................... 23
4.2.6. Undesirable Headers ................................... 23
4.3. Body ...................................................... 23
4.3.1. Body Format Issues .................................... 23
4.3.2. Body Conventions ...................................... 24
4.4. Characters and Character Sets ............................. 26
4.4.1. Character Sets within Article Headers ................. 26
4.4.2. Character Sets within Article Bodies .................. 27
4.5. Size Limits ............................................... 28
4.6. Example ................................................... 29
5. Mandatory Headers ............................................. 29
5.1. Date ...................................................... 30
5.1.1. Examples .............................................. 30
5.2. From ...................................................... 30
5.2.1. Examples: ............................................ 31
5.3. Message-ID ................................................ 32
5.4. Subject ................................................... 33
5.4.1. Examples .............................................. 34
5.5. Newsgroups ................................................ 34
5.5.1. Forbidden newsgroup names ............................. 39
5.6. Path ...................................................... 39
5.6.1. Format ................................................ 39
5.6.2. Adding a path-identity to the Path-header ............. 40
5.6.3. The tail-entry ........................................ 41
5.6.4. Path-Delimiter Summary ................................ 42
5.6.5. Suggested Verification Methods ........................ 43
5.6.6. Example ............................................... 43
6. Optional Headers .............................................. 44
6.1. Reply-To .................................................. 44
6.1.1. Examples .............................................. 44
6.2. Sender .................................................... 45
6.3. Organization .............................................. 45
6.4. Keywords .................................................. 45
6.5. Summary ................................................... 45
6.6. Distribution .............................................. 46
6.7. Followup-To ............................................... 47
6.8. Mail-Copies-To ............................................ 47
6.9. Posted-And-Mailed ......................................... 49
6.10. References ............................................... 49
6.10.1. Examples ............................................. 50
6.11. Expires .................................................. 50
6.12. Archive .................................................. 50
6.13. Control .................................................. 51
6.14. Approved ................................................. 52
6.15. Supersedes ............................................... 52
6.16. Xref ..................................................... 53
6.17. Lines .................................................... 54
6.18. User-Agent ............................................... 54
6.18.1. Examples ............................................. 55
6.19. Injector-Info ............................................ 55
6.19.1. Usage of Injector-Info-parameters .................... 57
6.19.1.1. The posting-host-parameter ....................... 58
6.19.1.2. The posting-account-parameter .................... 58
6.19.1.3. The posting-sender-parameter ..................... 58
6.19.1.4. The posting-logging-parameter .................... 58
6.19.1.5. The posting-date-parameter ....................... 58
6.19.2. Example .............................................. 59
6.20. Complaints-To ............................................ 59
6.21. MIME headers ............................................. 59
6.21.1. Syntax ............................................... 59
6.21.2. Content-Type ......................................... 60
6.21.2.1. Message/partial .................................. 60
6.21.2.2. Message/rfc822 ................................... 61
6.21.2.3. Message/external-body ............................ 62
6.21.2.4. Multipart types .................................. 62
6.21.3. Content-Transfer-Encoding ............................ 62
6.21.4. Character Sets ....................................... 64
6.21.5. Content Disposition .................................. 64
6.21.6. Definition of some new Content-Types ................. 64
6.21.6.1. Application/news-transmission .................... 64
6.21.6.2. Message/news obsoleted ........................... 66
6.22. Obsolete Headers ......................................... 66
7. Control Messages .............................................. 66
7.1. Digital Signature of Headers .............................. 67
7.2. Group Control Messages .................................... 67
7.2.1. The 'newgroup' Control Message ........................ 67
7.2.1.1. The Body of the 'newgroup' Control Message ........ 68
7.2.1.2. Application/news-groupinfo ........................ 68
7.2.1.3. Initial Articles .................................. 70
7.2.1.4. Example ........................................... 71
7.2.2. The 'rmgroup' Control Message ......................... 71
7.2.2.1. Example ........................................... 72
7.2.3. The 'mvgroup' Control Message ......................... 72
7.2.3.1. Example ........................................... 73
7.2.4. The 'checkgroups' Control Message ..................... 74
7.2.4.1. Application/news-checkgroups ...................... 75
7.3. Cancel .................................................... 76
7.4. Ihave, sendme ............................................. 77
7.5. Obsolete control messages. ............................... 78
8. Duties of Various Agents ...................................... 78
8.1. General principles to be followed ......................... 78
8.2. Duties of an Injecting Agent .............................. 79
8.2.1. Proto-articles ........................................ 79
8.2.2. Procedure to be followed by Injecting Agents .......... 79
8.3. Duties of a Relaying Agent ................................ 81
8.4. Duties of a Serving Agent ................................. 82
8.5. Duties of a Posting Agent ................................. 83
8.6. Duties of a Followup Agent ................................ 83
8.7. Duties of a Moderator ..................................... 84
8.8. Duties of a Gateway ....................................... 85
8.8.1. Duties of an Outgoing Gateway ......................... 86
8.8.2. Duties of an Incoming Gateway ......................... 88
8.8.3. Example ............................................... 90
9. Security and Related Considerations ........................... 90
9.1. Leakage ................................................... 91
9.2. Attacks ................................................... 91
9.2.1. Denial of Service ..................................... 91
9.2.2. Compromise of System Integrity ........................ 92
9.3. Liability ................................................. 93
10. IANA Considerations .......................................... 94
11. References ................................................... 94
12. Acknowledgements ............................................. 97
13. Contact Address .............................................. 97
Appendix A.1 - A-News Article Format .............................. 98
Appendix A.2 - Early B-News Article Format ........................ 99
Appendix A.3 - Obsolete Headers ................................... 99
Appendix A.4 - Obsolete Control Messages .......................... 100
Appendix B - Collected Syntax ..................................... 101
Appendix B.1 - Characters, Atoms and Folding ...................... 101
Appendix B.2 - Basic Forms ........................................ 103
Appendix B.3 - Headers ............................................ 104
Appendix B.3.1 - Header outlines .................................. 104
Appendix B.3.2 - Control-message outlines ......................... 106
Appendix B.3.3 - Other header rules ............................... 107
Appendix C - Notices .............................................. 109
1. Introduction
1.1. Basic Concepts
1.2. Objectives
1.3. Historical Outline
1.4. Transport
2. Definitions, Notations and Conventions
2.1. Definitions
2.2. Textual Notations
2.3. Relation To Email and MIME
2.4. Syntax
2.4.1. Syntax Notation
2.4.2. Syntax adapted from Email and MIME
2.4.3. Syntax copied from other standards
2.5. Language
3. Changes to the existing protocols
3.1. Principal Changes
3.2. Transitional Arrangements
4. Basic Format
4.1. Syntax of News Articles
4.2. Headers
4.2.1. Naming of Headers
4.2.2. MIME-style Parameters
4.2.3. White Space and Continuations
4.2.4. Comments
4.2.5. Header Properties
4.2.5.1. Experimental Headers
4.2.5.2. Inheritable Headers
4.2.5.3. Variant Headers
4.2.6. Undesirable Headers
4.3. Body
4.3.1. Body Format Issues
4.3.2. Body Conventions
4.4. Characters and Character Sets
4.4.1. Character Sets within Article Headers
4.4.2. Character Sets within Article Bodies
4.5. Size Limits
4.6. Example
5. Mandatory Headers
5.1. Date
5.1.1. Examples
5.2. From
5.2.1. Examples:
5.3. Message-ID
5.4. Subject
5.4.1. Examples
5.5. Newsgroups
5.5.1. Forbidden newsgroup names
5.6. Path
5.6.1. Format
5.6.2. Adding a path-identity to the Path-header
5.6.3. The tail-entry
5.6.4. Path-Delimiter Summary
5.6.5. Suggested Verification Methods
5.6.6. Example
6. Optional Headers
6.1. Reply-To
6.1.1. Examples
6.2. Sender
6.3. Organization
6.4. Keywords
6.5. Summary
6.6. Distribution
6.7. Followup-To
6.8. Mail-Copies-To
6.9. Posted-And-Mailed
6.10. References
6.10.1. Examples
6.11. Expires
6.12. Archive
6.13. Control
6.14. Approved
6.15. Supersedes
6.16. Xref
6.17. Lines
6.18. User-Agent
6.18.1. Examples
6.19. Injector-Info
6.19.1. Usage of Injector-Info-parameters
6.19.1.1. The posting-host-parameter
6.19.1.2. The posting-account-parameter
6.19.1.3. The posting-sender-parameter
6.19.1.4. The posting-logging-parameter
6.19.1.5. The posting-date-parameter
6.19.2. Example
6.20. Complaints-To
6.21. MIME headers
6.21.1. Syntax
6.21.2. Content-Type
6.21.2.1. Message/partial
6.21.2.2. Message/rfc822
6.21.2.3. Message/external-body
6.21.2.4. Multipart types
6.21.3. Content-Transfer-Encoding
6.21.4. Character Sets
6.21.5. Content Disposition
6.21.6. Definition of some new Content-Types
6.21.6.1. Application/news-transmission
6.21.6.2. Message/news obsoleted
6.22. Obsolete Headers
7. Control Messages
7.1. Digital Signature of Headers
7.2. Group Control Messages
7.2.1.2. Application/news-groupinfo
7.2.1.3. Initial Articles
7.2.1.4. Example
7.2.2.1. Example
7.2.3.1. Example
7.2.4.1. Application/news-checkgroups
7.3. Cancel
7.4. Ihave, sendme
7.5. Obsolete control messages.
8. Duties of Various Agents
8.1. General principles to be followed
8.2. Duties of an Injecting Agent
8.2.1. Proto-articles
8.2.2. Procedure to be followed by Injecting Agents
8.3. Duties of a Relaying Agent
8.4. Duties of a Serving Agent
8.5. Duties of a Posting Agent
8.6. Duties of a Followup Agent
8.7. Duties of a Moderator
8.8. Duties of a Gateway
8.8.1. Duties of an Outgoing Gateway
8.8.2. Duties of an Incoming Gateway
8.8.3. Example
9. Security and Related Considerations
9.1. Leakage
9.2. Attacks
9.2.1. Denial of Service
9.2.2. Compromise of System Integrity
9.3. Liability
10. IANA Considerations
11. References
12. Acknowledgements
13. Contact Address
[TOC] [ Next >]
#Diff to first older
--- ../usefor-article-06/TOC.out November 2001
+++ ../usefor-article-07/TOC.out May 2002
@@ -1,9 +1,9 @@
INTERNET-DRAFT Charles H. Lindsey
Usenet Format Working Group University of Manchester
- November 2001
+ May 2002
News Article Format
- <draft-ietf-usefor-article-06.txt>
+ <draft-ietf-usefor-article-07.txt>
Status of this Memo
@@ -29,15 +29,16 @@
Abstract
- This Draft defines the format of Netnews articles and specifies
- the requirements to be met by software which originates,
- distributes, stores and displays them. It is intended as a
- standards track document, superseding RFC 1036, which itself dates
- from 1987.
+ This Draft is intended as a standards track document, obsoleting
+ RFC 1036, which itself dates from 1987.
+
+ This Standard defines the format of Netnews articles and specifies
+ the requirements to be met by software which originates, distributes,
+ stores and displays them.
Since the 1980s, Usenet has grown explosively, and many Internet and
- non-Internet sites now participate. In addition, this technology is
- now in widespread use for other purposes.
+ non-Internet sites now participate. In addition, the Netnews
+ technology is now in widespread use for other purposes.
Backward compatibility has been a major goal of this endeavour, but
where this standard and earlier documents or practices conflict, this
@@ -52,155 +53,169 @@
[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
explain matters amongst ourselves, or to point out alternatives, or to
-indicate work yet to be done.]
+assist the RFC Editor.]
+
+[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-
+ietf-nntpext-base-*.txt, in the event that such RFC has been accepted at
+the time this document is published.]
-[Please note that this Draft describes "Work in Progress". Much remains
-to be done, though the material included so far is unlikely to change in
-any major way.]
+[Please note that this Draft is now close to Last Call, and the material
+included here is unlikely to change in any major way.]
Table of Contents
-1. Introduction .................................................. 5
- 1.1. Basic Concepts ............................................ 5
- 1.2. Objectives ................................................ 6
- 1.3. Historical Outline ........................................ 6
- 1.4. Transport ................................................. 6
-2. Definitions, Notations and Conventions ........................ 6
- 2.1. Definitions ............................................... 7
- 2.2. Textual Notations ......................................... 8
- 2.3. Relation To Mail and MIME ................................. 10
- 2.4. Syntax Notation ........................................... 10
- 2.5. Language .................................................. 13
-3. Changes to the existing protocols ............................. 13
- 3.1. Principal Changes ......................................... 13
- 3.2. Transitional Arrangements ................................. 14
-4. Basic Format .................................................. 15
- 4.1. Syntax of News Articles ................................... 15
- 4.2. Headers ................................................... 16
- 4.2.1. Names and Contents .................................... 16
- 4.2.2. Header Properties ..................................... 18
- 4.2.2.1. Experimental Headers .............................. 18
- 4.2.2.2. Inheritable Headers ............................... 18
- 4.2.2.3. Variant Headers ................................... 18
- 4.2.3. White Space and Continuations ......................... 19
- 4.2.4. Comments .............................................. 20
- 4.2.5. Undesirable Headers ................................... 20
- 4.3. Body ...................................................... 21
- 4.3.1. Body Format Issues .................................... 21
- 4.3.2. Body Conventions ...................................... 21
- 4.4. Characters and Character Sets ............................. 23
- 4.4.1. Character Sets within Article Headers ................. 23
- 4.4.2. Character Sets within Article Bodies .................. 25
- 4.5. Size Limits ............................................... 25
- 4.6. Example ................................................... 26
-5. Mandatory Headers ............................................. 27
- 5.1. Date ...................................................... 27
- 5.1.1. Examples .............................................. 28
- 5.2. From ...................................................... 28
- 5.2.1. Examples: ............................................ 28
- 5.3. Message-ID ................................................ 29
- 5.4. Subject ................................................... 29
- 5.4.1. Examples .............................................. 30
- 5.5. Newsgroups ................................................ 31
- 5.5.1. Forbidden newsgroup names ............................. 35
- 5.6. Path ...................................................... 36
- 5.6.1. Format ................................................ 36
- 5.6.2. Adding a path-identity to the Path header ............. 37
- 5.6.3. The tail-entry ........................................ 38
- 5.6.4. Delimiter Summary ..................................... 38
- 5.6.5. Suggested Verification Methods ........................ 39
- 5.6.6. Example ............................................... 40
-6. Optional Headers .............................................. 41
- 6.1. Reply-To .................................................. 41
- 6.1.1. Examples .............................................. 42
- 6.2. Sender .................................................... 42
- 6.3. Organization .............................................. 42
- 6.4. Keywords .................................................. 42
- 6.5. Summary ................................................... 42
- 6.6. Distribution .............................................. 43
- 6.7. Followup-To ............................................... 44
- 6.8. Mail-Copies-To ............................................ 44
- 6.9. Posted-And-Mailed ......................................... 46
- 6.10. References ............................................... 46
- 6.10.1. Examples ............................................. 47
- 6.11. Expires .................................................. 47
- 6.12. Archive .................................................. 47
- 6.13. Control .................................................. 48
- 6.14. Approved ................................................. 48
- 6.15. Supersedes ............................................... 49
- 6.16. Xref ..................................................... 49
- 6.17. Lines .................................................... 50
- 6.18. User-Agent ............................................... 50
- 6.18.1. Examples ............................................. 51
- 6.19. Injector-Info ............................................ 51
- 6.19.1. Usage of Injector-Info-header-parameters ............. 53
- 6.19.1.1. The posting-host-parameter ....................... 54
- 6.19.1.2. The posting-account-parameter .................... 54
- 6.19.1.3. The posting-sender-parameter ..................... 54
- 6.19.1.4. The posting-logging-parameter .................... 54
- 6.19.1.5. The posting-date-parameter ....................... 54
- 6.19.2. Example .............................................. 55
- 6.20. Complaints-To ............................................ 55
- 6.21. MIME headers ............................................. 55
- 6.21.1. Syntax ............................................... 55
- 6.21.2. Content-Type ......................................... 56
- 6.21.2.1. Message/partial .................................. 56
- 6.21.2.2. Message/rfc822 ................................... 57
- 6.21.2.3. Message/external-body ............................ 58
- 6.21.2.4. Multipart types .................................. 58
- 6.21.3. Content-Transfer-Encoding ............................ 58
- 6.21.4. Character Sets ....................................... 60
- 6.21.5. Content Disposition .................................. 60
- 6.21.6. Definition of some new Content-Types ................. 60
- 6.21.6.1. Application/news-transmission .................... 60
- 6.21.6.2. Message/news withdrawn ........................... 62
- 6.22. Obsolete Headers ......................................... 62
-7. Control Messages .............................................. 62
- 7.1. Digital Signature of Headers .............................. 63
- 7.2. Group Control Messages .................................... 63
- 7.2.1. The 'newgroup' Control Message ........................ 63
- 7.2.1.1. The Body of the 'newgroup' Control Message ........ 64
- 7.2.1.2. Application/news-groupinfo ........................ 64
- 7.2.1.3. Initial Articles .................................. 66
- 7.2.1.4. Example ........................................... 67
- 7.2.2. The 'rmgroup' Control Message ......................... 68
- 7.2.2.1. Example ........................................... 68
- 7.2.3. The 'mvgroup' Control Message ......................... 68
- 7.2.3.1. Example ........................................... 70
- 7.2.4. The 'checkgroups' Control Message ..................... 70
- 7.2.4.1. Application/news-checkgroups ...................... 71
- 7.3. Cancel .................................................... 72
- 7.4. Ihave, sendme ............................................. 73
- 7.5. Obsolete control messages. ............................... 74
-8. Duties of Various Agents ...................................... 74
- 8.1. General principles to be followed ......................... 74
- 8.2. Duties of an Injecting Agent .............................. 75
- 8.2.1. Proto-articles ........................................ 75
- 8.2.2. Procedure to be followed by Injecting Agents .......... 75
- 8.3. Duties of a Relaying Agent ................................ 77
- 8.4. Duties of a Serving Agent ................................. 78
- 8.5. Duties of a Posting Agent ................................. 79
- 8.6. Duties of a Followup Agent ................................ 79
- 8.7. Duties of a Moderator ..................................... 80
- 8.8. Duties of a Gateway ....................................... 81
- 8.8.1. Duties of an Outgoing Gateway ......................... 82
- 8.8.2. Duties of an Incoming Gateway ......................... 83
- 8.8.3. Example ............................................... 85
-9. Security and Related Considerations ........................... 86
- 9.1. Leakage ................................................... 86
- 9.2. Attacks ................................................... 86
- 9.2.1. Denial of Service ..................................... 86
- 9.2.2. Compromise of System Integrity ........................ 87
- 9.3. Liability ................................................. 88
-10. IANA Considerations .......................................... 89
-11. References ................................................... 89
-12. Acknowledgements ............................................. 91
-13. Contact Addresses ............................................ 91
-14. Intellectual Property Rights ................................. 92
-Appendix A.1 - A-News Article Format .............................. 93
-Appendix A.2 - Early B-News Article Format ........................ 93
-Appendix A.3 - Obsolete Headers ................................... 94
-Appendix A.4 - Obsolete Control Messages .......................... 94
-Appendix B - Collected Syntax ..................................... 95
+1. Introduction .................................................. 6
+ 1.1. Basic Concepts ............................................ 6
+ 1.2. Objectives ................................................ 7
+ 1.3. Historical Outline ........................................ 7
+ 1.4. Transport ................................................. 7
+2. Definitions, Notations and Conventions ........................ 8
+ 2.1. Definitions ............................................... 8
+ 2.2. Textual Notations ......................................... 9
+ 2.3. Relation To Email and MIME ................................ 10
+ 2.4. Syntax .................................................... 11
+ 2.4.1. Syntax Notation ....................................... 11
+ 2.4.2. Syntax adapted from Email and MIME .................... 11
+ 2.4.3. Syntax copied from other standards .................... 13
+ 2.5. Language .................................................. 14
+3. Changes to the existing protocols ............................. 15
+ 3.1. Principal Changes ......................................... 15
+ 3.2. Transitional Arrangements ................................. 15
+4. Basic Format .................................................. 17
+ 4.1. Syntax of News Articles ................................... 17
+ 4.2. Headers ................................................... 18
+ 4.2.1. Naming of Headers ..................................... 18
+ 4.2.2. MIME-style Parameters ................................. 19
+ 4.2.3. White Space and Continuations ......................... 20
+ 4.2.4. Comments .............................................. 21
+ 4.2.5. Header Properties ..................................... 22
+ 4.2.5.1. Experimental Headers .............................. 22
+ 4.2.5.2. Inheritable Headers ............................... 22
+ 4.2.5.3. Variant Headers ................................... 23
+ 4.2.6. Undesirable Headers ................................... 23
+ 4.3. Body ...................................................... 23
+ 4.3.1. Body Format Issues .................................... 23
+ 4.3.2. Body Conventions ...................................... 24
+ 4.4. Characters and Character Sets ............................. 26
+ 4.4.1. Character Sets within Article Headers ................. 26
+ 4.4.2. Character Sets within Article Bodies .................. 27
+ 4.5. Size Limits ............................................... 28
+ 4.6. Example ................................................... 29
+5. Mandatory Headers ............................................. 29
+ 5.1. Date ...................................................... 30
+ 5.1.1. Examples .............................................. 30
+ 5.2. From ...................................................... 30
+ 5.2.1. Examples: ............................................ 31
+ 5.3. Message-ID ................................................ 32
+ 5.4. Subject ................................................... 33
+ 5.4.1. Examples .............................................. 34
+ 5.5. Newsgroups ................................................ 34
+ 5.5.1. Forbidden newsgroup names ............................. 39
+ 5.6. Path ...................................................... 39
+ 5.6.1. Format ................................................ 39
+ 5.6.2. Adding a path-identity to the Path-header ............. 40
+ 5.6.3. The tail-entry ........................................ 41
+ 5.6.4. Path-Delimiter Summary ................................ 42
+ 5.6.5. Suggested Verification Methods ........................ 43
+ 5.6.6. Example ............................................... 43
+6. Optional Headers .............................................. 44
+ 6.1. Reply-To .................................................. 44
+ 6.1.1. Examples .............................................. 44
+ 6.2. Sender .................................................... 45
+ 6.3. Organization .............................................. 45
+ 6.4. Keywords .................................................. 45
+ 6.5. Summary ................................................... 45
+ 6.6. Distribution .............................................. 46
+ 6.7. Followup-To ............................................... 47
+ 6.8. Mail-Copies-To ............................................ 47
+ 6.9. Posted-And-Mailed ......................................... 49
+ 6.10. References ............................................... 49
+ 6.10.1. Examples ............................................. 50
+ 6.11. Expires .................................................. 50
+ 6.12. Archive .................................................. 50
+ 6.13. Control .................................................. 51
+ 6.14. Approved ................................................. 52
+ 6.15. Supersedes ............................................... 52
+ 6.16. Xref ..................................................... 53
+ 6.17. Lines .................................................... 54
+ 6.18. User-Agent ............................................... 54
+ 6.18.1. Examples ............................................. 55
+ 6.19. Injector-Info ............................................ 55
+ 6.19.1. Usage of Injector-Info-parameters .................... 57
+ 6.19.1.1. The posting-host-parameter ....................... 58
+ 6.19.1.2. The posting-account-parameter .................... 58
+ 6.19.1.3. The posting-sender-parameter ..................... 58
+ 6.19.1.4. The posting-logging-parameter .................... 58
+ 6.19.1.5. The posting-date-parameter ....................... 58
+ 6.19.2. Example .............................................. 59
+ 6.20. Complaints-To ............................................ 59
+ 6.21. MIME headers ............................................. 59
+ 6.21.1. Syntax ............................................... 59
+ 6.21.2. Content-Type ......................................... 60
+ 6.21.2.1. Message/partial .................................. 60
+ 6.21.2.2. Message/rfc822 ................................... 61
+ 6.21.2.3. Message/external-body ............................ 62
+ 6.21.2.4. Multipart types .................................. 62
+ 6.21.3. Content-Transfer-Encoding ............................ 62
+ 6.21.4. Character Sets ....................................... 64
+ 6.21.5. Content Disposition .................................. 64
+ 6.21.6. Definition of some new Content-Types ................. 64
+ 6.21.6.1. Application/news-transmission .................... 64
+ 6.21.6.2. Message/news obsoleted ........................... 66
+ 6.22. Obsolete Headers ......................................... 66
+7. Control Messages .............................................. 66
+ 7.1. Digital Signature of Headers .............................. 67
+ 7.2. Group Control Messages .................................... 67
+ 7.2.1. The 'newgroup' Control Message ........................ 67
+ 7.2.1.1. The Body of the 'newgroup' Control Message ........ 68
+ 7.2.1.2. Application/news-groupinfo ........................ 68
+ 7.2.1.3. Initial Articles .................................. 70
+ 7.2.1.4. Example ........................................... 71
+ 7.2.2. The 'rmgroup' Control Message ......................... 71
+ 7.2.2.1. Example ........................................... 72
+ 7.2.3. The 'mvgroup' Control Message ......................... 72
+ 7.2.3.1. Example ........................................... 73
+ 7.2.4. The 'checkgroups' Control Message ..................... 74
+ 7.2.4.1. Application/news-checkgroups ...................... 75
+ 7.3. Cancel .................................................... 76
+ 7.4. Ihave, sendme ............................................. 77
+ 7.5. Obsolete control messages. ............................... 78
+8. Duties of Various Agents ...................................... 78
+ 8.1. General principles to be followed ......................... 78
+ 8.2. Duties of an Injecting Agent .............................. 79
+ 8.2.1. Proto-articles ........................................ 79
+ 8.2.2. Procedure to be followed by Injecting Agents .......... 79
+ 8.3. Duties of a Relaying Agent ................................ 81
+ 8.4. Duties of a Serving Agent ................................. 82
+ 8.5. Duties of a Posting Agent ................................. 83
+ 8.6. Duties of a Followup Agent ................................ 83
+ 8.7. Duties of a Moderator ..................................... 84
+ 8.8. Duties of a Gateway ....................................... 85
+ 8.8.1. Duties of an Outgoing Gateway ......................... 86
+ 8.8.2. Duties of an Incoming Gateway ......................... 88
+ 8.8.3. Example ............................................... 90
+9. Security and Related Considerations ........................... 90
+ 9.1. Leakage ................................................... 91
+ 9.2. Attacks ................................................... 91
+ 9.2.1. Denial of Service ..................................... 91
+ 9.2.2. Compromise of System Integrity ........................ 92
+ 9.3. Liability ................................................. 93
+10. IANA Considerations .......................................... 94
+11. References ................................................... 94
+12. Acknowledgements ............................................. 97
+13. Contact Address .............................................. 97
+Appendix A.1 - A-News Article Format .............................. 98
+Appendix A.2 - Early B-News Article Format ........................ 99
+Appendix A.3 - Obsolete Headers ................................... 99
+Appendix A.4 - Obsolete Control Messages .......................... 100
+Appendix B - Collected Syntax ..................................... 101
+Appendix B.1 - Characters, Atoms and Folding ...................... 101
+Appendix B.2 - Basic Forms ........................................ 103
+Appendix B.3 - Headers ............................................ 104
+Appendix B.3.1 - Header outlines .................................. 104
+Appendix B.3.2 - Control-message outlines ......................... 106
+Appendix B.3.3 - Other header rules ............................... 107
+Appendix C - Notices .............................................. 109