INTERNET-DRAFT Charles H. Lindsey Usenet Format Working Group University of Manchester April 2001 News Article Format <draft-ietf-usefor-article-04.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 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. 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. 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 indicate work yet to be done.] [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.] Table of Contents 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 Mail and MIME 2.4. Syntax Notation 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. Names and Contents 4.2.2. Header Properties 4.2.2.1. Experimental Headers 4.2.2.2. Inheritable Headers 4.2.2.3. Local Headers 4.2.2.4. Variant Headers 4.2.3. White Space and Continuations 4.2.4. Comments 4.2.5. 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. 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. Replaces / Supersedes 6.15.1. Syntax and Semantics 6.15.2. Message-ID version procedure 6.15.2.1. Message version numbers 6.15.2.2. Implementation and Use Note 6.15.2.3. The Message-Version NNTP extension 6.15.2.4. Examples 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-header-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-Transfer-Encoding 6.21.3. Content-Type 6.21.3.1. Message/partial 6.21.3.2. Message/rfc822 6.21.3.3. Message/external-body 6.21.3.4. Multipart types 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 withdrawn 6.22. Obsolete Headers 7. Control Messages 7.1. The 'newgroup' Control Message 7.1.1. The Body of the 'newgroup' Control Message 7.1.2. Application/news-groupinfo 7.1.3. Initial Articles 7.1.4. Example 7.2. The 'rmgroup' Control Message 7.2.1. Example 7.3. The 'mvgroup' Control Message 7.3.1. Single group 7.3.2. Multiple Groups 7.3.3. Examples 7.4. The 'checkgroups' Control Message 7.4.1. Application/news-checkgroups 7.5. Cancel 7.6. Ihave, sendme 7.7. 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. References 11. Acknowledgements 12. Contact Addresses 13. Intellectual Property Rights Appendix A.1 - A-News Article Format Appendix A.2 - Early B-News Article Format Appendix A.3 - Obsolete Headers Appendix A.4 - Obsolete Control Messages Appendix B - Collected Syntax