Usenet Format Working Group C. Lindsey Internet-Draft University of Manchester Obsoletes: 1036 (if approved) K. Murchison Expires: March 15, 2005 Oceana Matrix Ltd. D. Kohn Skymoon Ventures September 14, 2004 News Article Format draft-ietf-usefor-usefor-01.txt Status of this Memo This document is an Internet-Draft and is subject to all provisions of section 3 of RFC 3667. By submitting this Internet-Draft, each author represents that any applicable patent or other IPR claims of which he or she is aware have been or will be disclosed, and any of which he or she become aware will be disclosed, in accordance with RFC 3668. 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. This Internet-Draft will expire on March 15, 2005. Copyright Notice Copyright (C) The Internet Society (2004). Abstract This document specifies the syntax of network news articles in the context of the "Internet Message Format" (RFC 2822) and "Multipurpose Internet Mail Extensions (MIME)" (RFC 2045). This document supersedes RFC 1036, updating it to reflect current practice and Lindsey, et al. Expires March 15, 2005 [Page 1] Internet-Draft News Article Format September 2004 incorporating incremental changes specified in other documents. Changes since draft-ietf-usefor-usefor-00 o Rewrote/reorganized Abstract and Introduction. o Added required SP to ABNF of header definitions. o Reorganized header sections. o Compatibility changes based on comments from Charles. o Added Injection-Date and Injection-Info headers. Changes since draft-ietf-usefor-article-13 o The Mail-Copies-To, Posted-And-Mailed and Complaints-To headers have been moved to other documents. o Dropped MIME parameters, as there is no WG consensus (per Chair). Issues to be addressed o Decide which definitions should go in this document and in [USEPRO]. o Decide how much (if any) discussion of Injection-Info content belongs in this document vs. [USEPRO]. o Do we want to discuss message/partial? o Add appendixes for obsolete headers, changes from RFC 1036 and differences from RFC 2822. o Merge more security issues? o Merge acknowledgments? Lindsey, et al. Expires March 15, 2005 [Page 2] Internet-Draft News Article Format September 2004 Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 4 1.1 Basic Concepts . . . . . . . . . . . . . . . . . . . . . . 4 1.2 Scope . . . . . . . . . . . . . . . . . . . . . . . . . . 4 1.3 Requirements Notation . . . . . . . . . . . . . . . . . . 5 1.4 Syntax Notation . . . . . . . . . . . . . . . . . . . . . 5 1.5 Definitions . . . . . . . . . . . . . . . . . . . . . . . 5 1.6 Structure of This Document . . . . . . . . . . . . . . . . 5 2. Format . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 2.1 Base . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 2.2 Header Fields . . . . . . . . . . . . . . . . . . . . . . 7 2.3 MIME Conformance . . . . . . . . . . . . . . . . . . . . . 8 2.4 Additional MIME Support . . . . . . . . . . . . . . . . . 8 3. News Headers . . . . . . . . . . . . . . . . . . . . . . . . 9 3.1 Mandatory Headers . . . . . . . . . . . . . . . . . . . . 9 3.1.1 From . . . . . . . . . . . . . . . . . . . . . . . . . 9 3.1.2 Subject . . . . . . . . . . . . . . . . . . . . . . . 9 3.1.3 Date . . . . . . . . . . . . . . . . . . . . . . . . . 9 3.1.4 Message-ID . . . . . . . . . . . . . . . . . . . . . . 10 3.1.5 Newsgroups . . . . . . . . . . . . . . . . . . . . . . 11 3.1.6 Path . . . . . . . . . . . . . . . . . . . . . . . . . 11 3.1.7 Injection-Date . . . . . . . . . . . . . . . . . . . . 12 3.2 Optional Headers . . . . . . . . . . . . . . . . . . . . . 12 3.2.1 References . . . . . . . . . . . . . . . . . . . . . . 13 3.2.2 Followup-To . . . . . . . . . . . . . . . . . . . . . 13 3.2.3 Expires . . . . . . . . . . . . . . . . . . . . . . . 13 3.2.4 Control . . . . . . . . . . . . . . . . . . . . . . . 13 3.2.5 Supersedes . . . . . . . . . . . . . . . . . . . . . . 14 3.2.6 Distribution . . . . . . . . . . . . . . . . . . . . . 14 3.2.7 Summary . . . . . . . . . . . . . . . . . . . . . . . 14 3.2.8 Approved . . . . . . . . . . . . . . . . . . . . . . . 15 3.2.9 Organization . . . . . . . . . . . . . . . . . . . . . 15 3.2.10 Xref . . . . . . . . . . . . . . . . . . . . . . . . 15 3.2.11 Archive . . . . . . . . . . . . . . . . . . . . . . 15 3.2.12 User-Agent . . . . . . . . . . . . . . . . . . . . . 16 3.2.13 Injection-Info . . . . . . . . . . . . . . . . . . . 16 4. Internationalization Considerations . . . . . . . . . . . . 18 5. Security Considerations . . . . . . . . . . . . . . . . . . 19 6. References . . . . . . . . . . . . . . . . . . . . . . . . . 20 6.1 Normative References . . . . . . . . . . . . . . . . . . . . 20 6.2 Informative References . . . . . . . . . . . . . . . . . . . 20 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . 21 A. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 23 Intellectual Property and Copyright Statements . . . . . . . 24 Lindsey, et al. Expires March 15, 2005 [Page 3] Internet-Draft News Article Format September 2004 1. Introduction 1.1 Basic Concepts "Netnews" is a set of protocols for generating, storing and retrieving news "articles" (which resemble email messages) and for exchanging them amongst a readership which is potentially widely distributed. It is organized around "newsgroups", with the expectation that each reader will be able to see all articles posted to each newsgroup in which he participates. These protocols most commonly use a flooding algorithm which propagates copies throughout a network of participating servers. Typically, only one copy is stored per server, and each server makes it available on demand to readers able to access that server. 1.2 Scope This document specifies the syntax of network news articles in the context of the "Internet Message Format" [RFC2822] and "Multipurpose Internet Mail Extensions (MIME)" [RFC2045]. This document supersedes [RFC1036], updating it to reflect current practice and incorporating incremental changes specified in other documents such as [Son-of-1036]. This is the first in a set of documents that obsolete [RFC1036]. This document focuses on the syntax and semantics of network news articles. [USEPRO] is also a standards-track document, and describes the protocol issues of network news articles, independent of transmission protocols such as NNTP [RFC0977]. An informational document, [USEAGE], describes implementation recommendations to improve interoperability and usability. This specification is intended as a definition of what article content format is to be passed between systems. Though some news systems locally store articles in this format (which eliminates the need for translation between formats) and others use formats that differ from the one specified in this standard, local storage is outside of the scope of this standard. Note: This standard is not intended to dictate the internal formats used by sites, the specific news system features that they are expected to support, or any of the characteristics of user interface programs that create or read articles. In addition, this standard does not specify an encoding of the characters for either transport or storage; that is, it does not specify the number of bits used or how those bits are specifically transferred over the wire or stored on disk. Lindsey, et al. Expires March 15, 2005 [Page 4] Internet-Draft News Article Format September 2004 1.3 Requirements Notation This document occasionally uses terms that appear in capital letters. The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in [RFC2119]. 1.4 Syntax Notation Headers defined in this specification use the Augmented Backus-Naur Form (ABNF) notation (including the Core Rules) specified in [RFC2234] and many constructs defined in [RFC2822]. Section 3.1.4 updates the [RFC2822] definition of . 1.5 Definitions An "article" is the unit of news, synonymous with an [RFC2822] "message". A "message identifier" Section 3.1.4 is a unique identifier for an article, usually supplied by the "posting agent" which posted it or, failing that, by the "injecting agent". It distinguishes the article from every other article ever posted anywhere. Articles with the same message identifier are treated as if they are the same article regardless of any differences in the body or headers. A "newsgroup" is a single news forum, a logical bulletin board, having a name and nominally intended for articles on a specific topic. An article is "posted to" a single newsgroup or several newsgroups. When an article is posted to more than one newsgroup, it is said to be "crossposted"; note that this differs from posting the same text as part of each of several articles, one per newsgroup. A newsgroup may be "moderated", in which case submissions are not posted directly, but mailed to a "moderator" for consideration and possible posting. Moderators are typically human but may be implemented partially or entirely in software. A "control message" is an article which is marked as containing control information; a relaying or serving agent receiving such an article may (subject to the policies observed at that site) take actions beyond just filing and passing on the article. 1.6 Structure of This Document This document uses a cite by reference methodology, rather than repeating the contents of other standards, which could otherwise result in subtle differences and interoperability challenges. Lindsey, et al. Expires March 15, 2005 [Page 5] Internet-Draft News Article Format September 2004 Although this document is as a result rather short, it requires complete understanding and implementation of the normative references to be compliant. Section 2 defines the format of news articles. Section 3 details the headers necessary to make an article suitable for the netnews environment. Lindsey, et al. Expires March 15, 2005 [Page 6] Internet-Draft News Article Format September 2004 2. Format 2.1 Base News articles MUST conform to the syntax specified in Section 3 of [RFC2822]. News agents MAY also accept the obsolete syntax specified in Section 4 of [RFC2822], but they MUST NOT generate such syntax. 2.2 Header Fields All headers fields in a news article are compliant with [RFC2822], however this specification is more restrictive in what can be generated and accepted by news agents. The syntax allowed for news articles is a strict subset of the "Internet Message Format", making all messages compliant with this specification inherently compliant with [RFC2822]. Note however that the converse is not guaranteed to be true. General rules which apply to all headers (even those documented in [RFC2822] and [RFC2045]) are listed below and those that apply to specific headers are described in the relevent sections of this document. User agents MUST generate headers so that at least one space immediately follows the ':' separating the header name and the header contents. As a result, an header as defined in Section 3.2.6 of [RFC2822] MUST NOT be empty (it will always contain at least a single space). News agents MAY accept headers which do not contain the required space. Compliant software MUST support headers of at least 998 octets. This is the only limit on the length of a header line prescribed by this standard. However, specific rules to the contrary may apply in particular cases (for example, according to [RFC2047] header lines containing encoded-words are limited to 76 octets). 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 total length of a header (in particular it may, by suitable folding, be made to exceed the 998 octets restriction pertaining to a single header line). The character set for headers is US-ASCII. Where the use of non-ASCII characters is required, they MUST be encoded using the MIME mechanisms defined in [RFC2045] and [RFC2231]. Lindsey, et al. Expires March 15, 2005 [Page 7] Internet-Draft News Article Format September 2004 2.3 MIME Conformance User agents MUST meet the definition of MIME-conformance in [RFC2049]. This level of MIME Conformance provides support for internationalization and multimedia in message bodies [RFC2045], and support for internationalization of headers [RFC2047]. Note that [Errata] currently exist for [RFC2046] and [RFC2231]. 2.4 Additional MIME Support User agents conformant with this document MAY support reassembly of message/partial MIME messages, as specified in Section 5.2.2 of [RFC2046] and MAY support generation of message/partial articles for excessively large articles. User agents SHOULD accept and MAY generate MIME extension header fields, including but not limited to Content-Disposition [RFC2183] and Content-Language [RFC3282]. Lindsey, et al. Expires March 15, 2005 [Page 8] Internet-Draft News Article Format September 2004 3. News Headers The following news headers (also known as header fields) extend the fields defined in section 3.6 of [RFC2822] as follows: fields =/ *( newsgroups / path / injection-date / followup-to / expires / control / supersedes / distribution / summary / approved / organization / xref / archive / user-agent / injection-info ) Each of these headers may occur at most once in a news article. 3.1 Mandatory Headers Each news article conformant with this specification MUST have exactly one of each of the following headers: From, Subject, Date, Message-ID, Newsgroups, Path, and Injection-Date. 3.1.1 From The From header is the same as that specified in Section 3.6.2 of [RFC2822] with the added restrictions detailed in Section 2.2. 3.1.2 Subject The Subject header is the same as that specified in Section 3.6.5 of [RFC2822] with the added restrictions detailed in Section 2.2. Further discussion of the content of the Subject header is discussed in [USEPRO] and [USEAGE]. 3.1.3 Date The Date header is the same as that specified in Sections 3.3 and 3.6.1 of [RFC2822] with the added restrictions detailed in Section 2.2. However, the use of "GMT" and "UT" as time zones, which are part of , is widespread in news articles today. Therefore, agents MUST accept, but MUST NOT generate, constructs Lindsey, et al. Expires March 15, 2005 [Page 9] Internet-Draft News Article Format September 2004 which include . As stated in Section 2.1, support for would otherwise have been SHOULD accept, MUST NOT generate. Note that these requirements apply wherever is used, including Injection-Date and Expires in Section 3.1.7 and Section 3.2.3 respectively. 3.1.4 Message-ID The Message-ID header contains a single unique message identifier. This document updates the construct from Section 3.6.4 of [RFC2822] so as to ensure that Internet Message Format Message-IDs are usable in widely deployed news software. The ABNF should be used as below, but the requirements and descriptive text from Section 3.6.4 of [RFC2822] still apply. message-id = "Message-ID:" SP msg-id CRLF msg-id = [FWS] msg-id-core [FWS] msg-id-core = "<" id-left "@" id-right ">" ; maximum length is 250 octets id-left = dot-atom-text / no-fold-quote / obs-id-left id-right = dot-atom-text / no-fold-literal / obs-id-right no-fold-quote = DQUOTE *( qtext / no-space-qp ) DQUOTE no-fold-literal = "[" *( htext / no-space-qp ) "]" no-space-qp = ( "\" ptext ) / obs-qp ptext = %d33-61 / ; Printable characters excluding ">" %d63-126 / obs-text htext = HEXDIG / ; hexadecimal digits, case-insensitive "." / ; IPv4 separator ":" ; IPv6 separator The msg-id-core MUST NOT be more than 250 octets in length. NOTE: The length restriction ensures that systems which accept message identifiers as a parameter when retrieving an article (e.g. NNTP [RFC0977]) can rely on a bounded length. Observe that msg-id-core includes the < and >. Observe that in contrast to the corresponding header in [RFC2822], Lindsey, et al. Expires March 15, 2005 [Page 10] Internet-Draft News Article Format September 2004 the syntax does not allow comments within the Message-ID header; this is to simplify processing by relaying and serving agents and to ensure interoperability with existing implementations. Also note that this updated ABNF applies wherever is used, including the References header discussed in Section 3.2.1. 3.1.5 Newsgroups The Newsgroups header specifies the newsgroup(s) to which the article is posted. newsgroups = "Newsgroups:" SP newsgroup-list CRLF newsgroup-list = [FWS] newsgroup-name *( "," [FWS] newsgroup-name ) [FWS] newsgroup-name = component *( "." component ) ; 66 character max component = plain-component plain-component = component-start *29component-rest component-start = ALPHA / DIGIT component-rest = ALPHA / DIGIT / "+" / "-" / "_" A newsgroup name consists of one or more components separated by periods, with no more than 66 characters total. Each component consists of less than 30 or less letters and digits. These limits are discussed further in Section 7.2 of [USEAGE]. 3.1.6 Path The Path header indicates the route taken by an article since its entry into the Netnews system, so that unnecessary redundant transmission can be avoided. path = "Path:" SP path-list CRLF path-list = [FWS] path-identity *( path-delimiter [FWS] path-identity ) [FWS] path-identity = ( ALPHA / DIGIT ) *( ALPHA / DIGIT / "-" / "." / ":" / "_" ) path-delimiter = "!" Lindsey, et al. Expires March 15, 2005 [Page 11] Internet-Draft News Article Format September 2004 3.1.7 Injection-Date The Injection-Date header contains the date and time that the article was injected into the network. Its purpose is to prevent the reinjection into the news stream of "stale" articles which have already expired by the time they arrive at some relaying or serving agent. This header is mandatory for new clients, but all agents SHOULD use the Date header for this purpose if Injection-Date is not present. injection-date = "Injection-Date:" SP date-time CRLF See the remarks under Section 3.1.3 regarding the syntax of date-time and the requirements and recommendations to which it is subject. NOTE: The date-time in this header would normally be expected to be later than the date-time in the Date header, but differences between the clocks on the various agents and other special circumstances might vitiate that; no provision is made for any such discrepancy to be corrected - better that the injecting agent should just insert the correct time as it sees it. This header is intended to replace the currently-used but undocumented "NNTP-Posting-Date" header, whose use is now deprecated. 3.2 Optional Headers None of the headers appearing in this section is required to appear in every article but some of them are required in certain types of article, such as followups. Further discussion of these requirements is discussed in [USEPRO] and [USEAGE]. The headers Reply-To, Sender, Comments, and Keywords are often used in news articles and have the identical meaning as that specified in [RFC2822] with the added restrictions detailed in Section 2.2. The MIME headers Content-Type and Content-Transfer-Encoding are often used in news articles and have the identical meaning as that specified in [RFC2045] with the added restrictions detailed in Section 2.2. All other commonly used news headers are described below. Lindsey, et al. Expires March 15, 2005 [Page 12] Internet-Draft News Article Format September 2004 3.2.1 References The References header is the same as that specified in Section 3.6.4 of [RFC2822] with the added restrictions detailed in Section 2.2 and those listed below: o The updated construct defined in Section 3.1.4 MUST be used. o Message IDs MUST be separated with CFWS. o Comments in CFWS between Message IDs can cause interoperability problems, so comments SHOULD NOT be generated, but MUST be accepted. 3.2.2 Followup-To The Followup-To header specifies to which newsgroup(s) followups should be posted. followup-to = "Followup-To:" SP ( newsgroup-list / poster-text ) CRLF poster-text = [FWS] %d112.111.115.116.101.114 [FWS] ; "poster" in lower-case The syntax is the same as that of the Newsgroups header (Section 3.1.5, with the exception that the magic word "poster" (which is always lowercase) means that followups should be mailed to the article's reply address rather than posted. In order to improve interoperability with deployed clients, followup agents MAY choose to recognize case-insensitive forms such as "Poster". 3.2.3 Expires The Expires header specifies a date and time when the article is deemed to be no longer useful and could usefully be removed ("expired"). expires = "Expires:" SP date-time CRLF See the remarks under Section 3.1.3 regarding the syntax of date-time and the requirements and recommendations to which it is subject. 3.2.4 Control The Control header marks the article as a control message, and specifies the desired actions (additional to the usual ones of storing and/or relaying the article). Lindsey, et al. Expires March 15, 2005 [Page 13] Internet-Draft News Article Format September 2004 control = "Control:" SP [CFWS] control-message [CFWS] CRLF control-message = The control-message indicates what action should be taken. The exact syntax for control-message is specified in the companion document, [USEPRO]. 3.2.5 Supersedes The Supersedes header contains a message identifier specifying an article to be superseded upon the arrival of this one. The specified article MUST be treated as though a "cancel" [USEPRO] control message had arrived for the article (but observe that a site MAY choose not to honor a "cancel" message, especially if its authenticity is in doubt). supersedes = "Supersedes:" SP [CFWS] msg-id-core [CFWS] CRLF NOTE: There is no "c" in Supersedes. 3.2.6 Distribution The Distribution header specifies geographic or organizational limits on an article's propagation. distribution = "Distribution:" SP dist-list CRLF list-list = [FWS] dist-name *( "," [FWS] dist-name ) [FWS] dist-name = ALPHA / DIGIT *( ALPHA / DIGIT / "+" / "-" / "_" ) "All" MUST NOT be used as a distribution-name. Distribution-names SHOULD contain at least three characters, except when they are two-letter country names as in [ISO.3166.1988]. Distribution-names are case-insensitive (i.e. "US", "Us", "uS", and "us" all specify the same distribution). 3.2.7 Summary The Summary header is a short phrase summarizing the article's content. summary = "Summary:" SP unstructured CRLF Lindsey, et al. Expires March 15, 2005 [Page 14] Internet-Draft News Article Format September 2004 3.2.8 Approved The Approved header indicates the mailing addresses (and possibly the full names) of the moderators approving the article for posting. approved = "Approved:" SP mailbox-list CRLF 3.2.9 Organization The Organization header is a short phrase identifying the poster's organization. organization = "Organization:" SP unstructured CRLF There is no "s" in Organization. 3.2.10 Xref The Xref header indicates where an article was filed by the last serving agent to process it. xref = "Xref:" SP [CFWS] server-name 1*( CFWS location ) [CFWS] CRLF server-name = path-identity location = newsgroup-name ":" article-locator article-locator = 1*( %x21-27 / %x29-3A / %x3C-7E ) ; US-ASCII printable characters ; except '(' and ';' The server-name is included so that software can determine which serving agent generated the header. The locations specify what newsgroups the article was filed under (which may differ from those in the Newsgroups-header) and where it was filed under them. The exact form of an article-locator is implementation-specific. NOTE: The traditional form of an article-locator (as used by NNTP) is a decimal number, with articles in each newsgroup numbered consecutively starting from 1. 3.2.11 Archive The Archive header provides an indication of the poster's intent regarding preservation of the article in publicly accessible long-term or permanent storage. Lindsey, et al. Expires March 15, 2005 [Page 15] Internet-Draft News Article Format September 2004 archive = "Archive:" SP [CFWS] ("no" / "yes") *( [CFWS] ";" archive-param ) CRLF archive-param = 3.2.12 User-Agent The User-Agent header contains information about the user agent (typically a newsreader) generating the article for statistical purposes and tracing of standards violations to specific software needing correction. Although not one of the mandatory headers, posting agents SHOULD normally include it. It is also intended that this header be suitable for use in Email. user-agent = "User-Agent:" SP 1*product CRLF product = [CFWS] token [CFWS] [ "/" product-version ] product-version = [CFWS] token [CFWS] 3.2.13 Injection-Info The Injection-Info header provides information as to how an article entered the Netnews system and to assist in tracing its true origin. Lindsey, et al. Expires March 15, 2005 [Page 16] Internet-Draft News Article Format September 2004 injection-info = "Injection-Info:" SP [CFWS] path-identity [CFWS] *( ";" injection-info-parameter ) injection-info-parameter = posting-host-parameter / posting-account-parameter / posting-sender-parameter / posting-logging-parameter posting-host-parameter = host-value = dot-atom / [ dot-atom ":" ] ( IPv4address / IPv6address ) ; see [RFC 2373] posting-account-parameter = posting-sender-parameter = sender-value = mailbox / "verified" posting-logging-parameter = Although comments and folding of white space are permitted throughout the Injection-Info header, it is RECOMMENDED that folding is not used within any parameter (but only before or after the ";" separating those parameters), and that comments are only used following the last parameter. It is also RECOMMENDED that such parameters as are present are included in the order in which they have been defined in the syntax above. This header is intended to replace various currently-used but undocumented headers such as "NNTP-Posting-Host" and "X-Trace". These headers are now deprecated. Lindsey, et al. Expires March 15, 2005 [Page 17] Internet-Draft News Article Format September 2004 4. Internationalization Considerations Internationalization of news article headers and bodies is provided using MIME mechanisms discussed in Section 2.3. Note that the generation of internationalized newsgroup names for use in headers is not addressed in this document. Lindsey, et al. Expires March 15, 2005 [Page 18] Internet-Draft News Article Format September 2004 5. Security Considerations The news article format specified in this document does not provide any security services, such as confidentiality, authentication of sender, or non-repudiation. Instead, such services need to be layered above, using such protocols as S/MIME [RFC2633] or PGP/MIME [RFC3156], or below, using secure versions of news transport protocols. Additionally, several currently non-standardized protocols [PGPVERIFY] will hopefully be standardized in the near future. Message-IDs (Section 3.1.4) in news are required to be unique; articles are refused (in server-to-server transfer) if the ID has already been seen. So if you can predict the ID of a message, you can preempt it by posting a message (possibly to a quite different group) with the same ID, stopping your target message from propagating. Agents that generate message-ids for news articles SHOULD ensure that they are unpredictable. The filename parameter of the Archive-header (Section 3.2.11) can be used to attempt to store archived articles in inappropriate locations. Archiving sites should be suspicious of absolute filename parameters, as opposed to those relative to some location of the archiver's choosing. Lindsey, et al. Expires March 15, 2005 [Page 19] Internet-Draft News Article Format September 2004 6. References 6.1 Normative References [Errata] "RFC Editor Errata". [RFC2045] Freed, N. and N. Borenstein, "Multipurpose Internet Mail Extensions (MIME) Part One: Format of Internet Message Bodies", RFC 2045, November 1996. [RFC2046] Freed, N. and N. Borenstein, "Multipurpose Internet Mail Extensions (MIME) Part Two: Media Types", RFC 2046, November 1996. [RFC2047] Moore, K., "MIME (Multipurpose Internet Mail Extensions) Part Three: Message Header Extensions for Non-ASCII Text", RFC 2047, November 1996. [RFC2049] Freed, N. and N. Borenstein, "Multipurpose Internet Mail Extensions (MIME) Part Five: Conformance Criteria and Examples", RFC 2049, November 1996. [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, March 1997. [RFC2183] Troost, R., Dorner, S. and K. Moore, "Communicating Presentation Information in Internet Messages: The Content-Disposition Header Field", RFC 2183, August 1997. [RFC2231] Freed, N. and K. Moore, "MIME Parameter Value and Encoded Word Extensions: Character Sets, Languages, and Continuations", RFC 2231, November 1997. [RFC2234] Crocker, D. and P. Overell, "Augmented BNF for Syntax Specifications: ABNF", RFC 2234, November 1997. [RFC2822] Resnick, P., "Internet Message Format", RFC 2822, April 2001. [RFC3282] Alvestrand, H., "Content Language Headers", RFC 3282, May 2002. 6.2 Informative References [ISO.3166.1988] International Organization for Standardization, "Codes for the representation of names of countries, 3rd edition", ISO Standard 3166, August 1988. Lindsey, et al. Expires March 15, 2005 [Page 20] Internet-Draft News Article Format September 2004 [PGPVERIFY] Lawrence, D., "PGPverify", June 1999. [RFC0977] Kantor, B. and P. Lapsley, "Network News Transfer Protocol", RFC 977, February 1986. [RFC1036] Horton, M. and R. Adams, "Standard for interchange of USENET messages", RFC 1036, December 1987. [RFC2633] Ramsdell, B., "S/MIME Version 3 Message Specification", RFC 2633, June 1999. [RFC3156] Elkins, M., Del Torto, D., Levien, R. and T. Roessler, "MIME Security with OpenPGP", RFC 3156, August 2001. [Son-of-1036] Spencer, H., "News Article Format and Transmission", June 1994. [USEAGE] Lindsey, C., "Usenet Best Practice", draft-ietf-usefor-useage-*.txt. [USEPRO] Lindsey, C., "News Article Architecture and Protocols", draft-ietf-usefor-usepro-*.txt. Authors' Addresses Charles H. Lindsey University of Manchester 5 Clerewood Avenue Heald Green Cheadle Chesire SK8 3JU GB Phone: +44 161 436 6131 EMail: chl@clw.cs.man.ac.uk Kenneth Murchison Oceana Matrix Ltd. 21 Princeton Place Orchard Park, NY 14127 US Phone: +1 716 662 8973 EMail: ken@oceana.com Lindsey, et al. Expires March 15, 2005 [Page 21] Internet-Draft News Article Format September 2004 Dan Kohn Skymoon Ventures 3045 Park Boulevard Palo Alto, CA 94306 US Phone: +1 650 327 2600 EMail: dan@dankohn.com Lindsey, et al. Expires March 15, 2005 [Page 22] Internet-Draft News Article Format September 2004 Appendix A. Acknowledgements Comments and/or text were provided by Mark Crispin, Claus Faerber, Ned Freed, Andrew Gierth, Tony Hansen, Paul Hoffman, Simon Josefsson, Bruce Lilly, Pete Resnick, and Henry Spencer. Lindsey, et al. Expires March 15, 2005 [Page 23] Internet-Draft News Article Format September 2004 Intellectual Property Statement The IETF takes no position regarding the validity or scope of any Intellectual Property Rights or other rights that might be claimed to pertain to the implementation or use of the technology described in this document or the extent to which any license under such rights might or might not be available; nor does it represent that it has made any independent effort to identify any such rights. Information on the procedures with respect to rights in RFC documents can be found in BCP 78 and BCP 79. 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Disclaimer of Validity This document and the information contained herein are provided on an "AS IS" basis and THE CONTRIBUTOR, THE ORGANIZATION HE/SHE REPRESENTS OR IS SPONSORED BY (IF ANY), THE INTERNET SOCIETY AND THE INTERNET ENGINEERING TASK FORCE DISCLAIM ALL WARRANTIES, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE INFORMATION HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. Copyright Statement Copyright (C) The Internet Society (2004). This document is subject to the rights, licenses and restrictions contained in BCP 78, and except as set forth therein, the authors retain all their rights. Acknowledgment Funding for the RFC Editor function is currently provided by the Internet Society. Lindsey, et al. Expires March 15, 2005 [Page 24]