draft-ietf-usefor-usepro-03.txt   draft-ietf-usefor-usepro-04.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 2005 July 2005
News Article Architecture and Protocols News Article Architecture and Protocols
<draft-ietf-usefor-usepro-03.txt> <draft-ietf-usefor-usepro-04.txt>
Status of this Memo Status of this Memo
By submitting this Internet-Draft, I certify that any applicable By submitting this Internet-Draft, each author represents that any
patent or other IPR claims of which I am aware have been applicable patent or other IPR claims of which he or she is aware
disclosed, or will be disclosed, and any of which I become aware have been or will be disclosed, and any of which he or she becomes
will be disclosed, in accordance with RFC 3668. aware will be disclosed, in accordance with Section 6 of BCP 79.
.QP Internet-Drafts are working documents of the Internet
Internet-Drafts are working documents of the Internet Engineering Engineering Task Force (IETF), its areas, and its working groups.
Task Force (IETF), its areas, and its working groups. Note that Note that other groups may also distribute working documents as
other groups may also distribute working documents as Internet- Internet-Drafts.
Drafts.
Internet-Drafts are draft documents valid for a maximum of six Internet-Drafts are draft documents valid for a maximum of six
months and may be updated, replaced, or obsoleted by other months and may be updated, replaced, or obsoleted by other
documents at any time. It is inappropriate to use Internet-Drafts documents at any time. It is inappropriate to use Internet-Drafts
as reference material or to cite them other than as "work in as reference material or to cite them other than as "work in
progress." progress."
The list of current Internet-Drafts can be accessed at The list of current Internet-Drafts can be accessed at
http://www.ietf.org/ietf/1id-abstracts.html. http://www.ietf.org/ietf/1id-abstracts.html.
The list of Internet-Draft Shadow Directories can be accessed at The list of Internet-Draft Shadow Directories can be accessed at
http://www.ietf.org/shadow.html. http://www.ietf.org/shadow.html.
This Internet-Draft will expire in August 2005. This Internet-Draft will expire in January 2006.
Abstract Abstract
This Draft, together with its companion draft [USEFOR], are This Draft, together with its companion draft [USEFOR], are
intended as standards track documents, together obsoleting RFC intended as standards track documents, together obsoleting RFC
1036, which itself dates from 1987. 1036, which itself dates from 1987.
This Standard defines the architecture of Netnews systems and This Standard defines the architecture of Netnews systems and
specifies the requirements to be met by software which originates, specifies the requirements to be met by software which originates,
distributes, stores and displays Netnews articles. distributes, stores and displays Netnews articles.
skipping to change at page 2, line 4 skipping to change at page 1, line 56
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.
A companion Current Best Practice document [USEAGE], addressing A companion Current Best Practice document [USEAGE], addressing
requirements which are present for Social rather than Normative requirements which are present for Social rather than Normative
News Article Architecture and Protocols February 2005
reasons is in preparation. reasons is in preparation.
News Article Architecture and Protocols July 2005
[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.]
[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.]
skipping to change at page 2, line 33 skipping to change at page 2, line 31
Table of Contents Table of Contents
1. Introduction .................................................. 4 1. Introduction .................................................. 4
1.1. Basic Concepts ............................................ 4 1.1. Basic Concepts ............................................ 4
1.2. Objectives ................................................ 5 1.2. Objectives ................................................ 5
1.3. Historical Outline ........................................ 5 1.3. Historical Outline ........................................ 5
2. Definitions, Notations and Conventions ........................ 6 2. Definitions, Notations and Conventions ........................ 6
2.1. Definitions ............................................... 6 2.1. Definitions ............................................... 6
2.2. Defining the Architecture ................................. 7 2.2. Defining the Architecture ................................. 7
2.3. Variant Headers ........................................... 8 2.3. Identification of news-servers ............................ 8
2.4. Textual Notations ......................................... 9 2.4. Variant Header Fields ..................................... 9
3. Changes to the existing protocols ............................. 9 2.5. Textual Notations ......................................... 9
3. Changes to the existing protocols ............................. 10
3.1. Principal Changes ......................................... 10 3.1. Principal Changes ......................................... 10
3.2. Transitional Arrangements ................................. 10 3.2. Transitional Arrangements ................................. 11
4. Transport ..................................................... 11 4. Transport ..................................................... 12
5. Definition of new Media Types ................................. 12 5. Definition of new Media Types ................................. 13
5.1. Application/news-transmission ............................. 12 5.1. Application/news-transmission ............................. 13
5.2. Message/news obsoleted .................................... 13 5.2. Message/news obsoleted .................................... 14
5.3. Application/news-groupinfo ................................ 13 5.3. Application/news-groupinfo ................................ 14
5.4. Application/news-checkgroups .............................. 14 5.4. Application/news-checkgroups .............................. 15
6. Control Messages .............................................. 15 6. Control Messages .............................................. 16
6.1. Digital Signature of Headers .............................. 16 6.1. Digital Signature of Header Fields ........................ 17
6.2. Group Control Messages .................................... 16 6.2. Group Control Messages .................................... 17
6.2.1. The 'newgroup' Control Message ........................ 16 6.2.1. The 'newgroup' Control Message ........................ 18
6.2.1.1. The Body of the 'newgroup' Control Message ........ 17 6.2.1.1. The Body of the 'newgroup' Control Message ........ 18
6.2.1.2. Initial Articles .................................. 17 6.2.1.2. Initial Articles .................................. 18
6.2.1.3. Example ........................................... 18 6.2.1.3. Example ........................................... 19
6.2.2. The 'rmgroup' Control Message ......................... 19 6.2.2. The 'rmgroup' Control Message ......................... 20
6.2.2.1. Example ........................................... 19 6.2.2.1. Example ........................................... 20
6.2.3. The 'mvgroup' Control Message ......................... 19 6.2.3. The 'mvgroup' Control Message ......................... 20
6.2.3.1. Example ........................................... 21 6.2.3.1. Example ........................................... 22
6.2.4. The 'checkgroups' Control Message ..................... 21 6.2.4. The 'checkgroups' Control Message ..................... 23
6.3. Cancel .................................................... 23 6.3. Cancel .................................................... 24
6.4. Ihave, sendme ............................................. 23 6.4. Ihave, sendme ............................................. 25
6.5. Obsolete control messages. ............................... 25 6.5. Obsolete control messages. ............................... 26
7. Duties of Various Agents ...................................... 25 7. Duties of Various Agents ...................................... 26
7.1. General principles to be followed ......................... 27
News Article Architecture and Protocols February 2005 News Article Architecture and Protocols July 2005
7.1. General principles to be followed ......................... 26 7.2. Duties of an Injecting Agent .............................. 27
7.2. Duties of an Injecting Agent .............................. 26 7.2.1. Proto-articles ........................................ 28
7.2.1. Proto-articles ........................................ 27 7.2.2. Procedure to be followed by Injecting Agents .......... 28
7.2.2. Procedure to be followed by Injecting Agents .......... 27 7.2.3. Procedure for Forwarding to a Moderator ............... 31
7.2.3. Procedure for Forwarding to a Moderator ............... 30 7.3. Duties of a Relaying Agent ................................ 31
7.3. Duties of a Relaying Agent ................................ 30 7.3.1. Path Header Field Example ............................. 34
7.3.1. Path-Header Example ................................... 33 7.4. Duties of a Serving Agent ................................. 35
7.4. Duties of a Serving Agent ................................. 34 7.5. Duties of a Posting Agent ................................. 36
7.5. Duties of a Posting Agent ................................. 35 7.6. Duties of a Followup Agent ................................ 37
7.6. Duties of a Followup Agent ................................ 36 7.6.1. Construction of the References header field ........... 37
7.7. Duties of a Reading Agent ................................. 37 7.7. Duties of a Reading Agent ................................. 38
7.8. Duties of a Moderator ..................................... 37 7.8. Duties of a Moderator ..................................... 38
7.9. Duties of a Gateway ....................................... 39 7.9. Duties of a Gateway ....................................... 40
7.9.1. Duties of an Outgoing Gateway ......................... 40 7.9.1. Duties of an Outgoing Gateway ......................... 41
7.9.2. Duties of an Incoming Gateway ......................... 41 7.9.2. Duties of an Incoming Gateway ......................... 42
7.9.3. Example ............................................... 43 7.9.3. Example ............................................... 44
8. Security and Related Considerations ........................... 44 8. Security and Related Considerations ........................... 45
8.1. Leakage ................................................... 44 8.1. Leakage ................................................... 45
8.2. Attacks ................................................... 44 8.2. Attacks ................................................... 45
8.2.1. Denial of Service ..................................... 44 8.2.1. Denial of Service ..................................... 45
8.2.2. Compromise of System Integrity ........................ 46 8.2.2. Compromise of System Integrity ........................ 46
8.3. Liability ................................................. 47 8.3. Liability ................................................. 48
9. IANA Considerations ........................................... 47 9. IANA Considerations ........................................... 48
10. References ................................................... 48 10. References ................................................... 48
11. Acknowledgements ............................................. 49 10.1. Normative References ..................................... 48
12. Contact Address .............................................. 49 10.2. Informative References ................................... 49
Appendix A.1 - A-News Article Format .............................. 49 11. Acknowledgements ............................................. 50
Appendix A.2 - Early B-News Article Format ........................ 50 12. Contact Address .............................................. 50
Appendix A.3 - Obsolete Control Messages .......................... 51 Appendix A.1 - A-News Article Format .............................. 50
Appendix B - Notices .............................................. 51 Appendix A.2 - Early B-News Article Format ........................ 51
Appendix C - Change Log ........................................... 52 Appendix A.3 - Obsolete Control Messages .......................... 52
Appendix B - Notices .............................................. 52
Appendix C - Change Log ........................................... 53
News Article Architecture and Protocols February 2005 News Article Architecture and Protocols July 2005
[This draft [USEPRO] and its partner [USEFOR] are an interim stage in [This draft [USEPRO] and its partner [USEFOR] are an interim stage in
the splitting into two parts of the earlier draft [ARTICLE]. There is a the splitting into two parts of the earlier draft [ARTICLE]. There is a
certain amount of material - basic concepts, definitions, etc - which certain amount of material - basic concepts, definitions, etc - which
ultimately need occur in only one of the documents, and further such ultimately need occur in only one of the documents, and further such
material which may not be needed at all (e.g. terms currently defined material which may not be needed at all (e.g. terms currently defined
which in the event may not get used). For the moment, all such material which in the event may not get used). For the moment, all such material
has been retained in the present draft (it being, in any case, easier to has been retained in the present draft (it being, in any case, easier to
take unwanted stuff out than to put new stuff in). It has also to be take unwanted stuff out than to put new stuff in). It has also to be
decided, for such material which is needed by both documents, which one decided, for such material which is needed by both documents, which one
skipping to change at page 5, line 5 skipping to change at page 5, line 5
A "policy" is a rule intended to facilitate the smooth operation of a A "policy" is a rule intended to facilitate the smooth operation of a
network by establishing parameters which restrict behaviour that, network by establishing parameters which restrict behaviour that,
whilst technically unexceptionable, would nevertheless contravene whilst technically unexceptionable, would nevertheless contravene
some accepted standard of "Good Netkeeping". Since the ultimate some accepted standard of "Good Netkeeping". Since the ultimate
beneficiaries of a network are its human readers, who will be less beneficiaries of a network are its human readers, who will be less
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.
News Article Architecture and Protocols February 2005 News Article Architecture and Protocols July 2005
1.2. Objectives 1.2. Objectives
The purpose of this present standard is to define the overall The purpose of this present standard is to define the overall
architecture and the protocols to be used for Netnews in general, and architecture and the protocols to be used for Netnews in general, and
for Usenet in particular, and to set standards to be followed by for Usenet in particular, and to set standards to be followed by
software that implements those protocols. A companion standard software that implements those protocols. A companion standard
[USEFOR] sets out the canonical format of news articles exchanged [USEFOR] sets out the canonical format of news articles exchanged
between the various agents comprising that architecture. In this between the various agents comprising that architecture. In this
standard, references to sections in the companion [USEFOR] are standard, references to sections in the companion [USEFOR] are
skipping to change at page 5, line 44 skipping to change at page 5, line 44
Internet and non-Internet sites participate in it. In addition, the Internet and non-Internet sites participate in it. In addition, the
news technology is now in widespread use for other purposes, on the news technology is now in widespread use for other purposes, on the
Internet and elsewhere. Internet and elsewhere.
The earliest news interchange used the so-called "A News" article The earliest news interchange used the so-called "A News" article
format. Shortly thereafter, an article format vaguely resembling format. Shortly thereafter, an article format vaguely resembling
Internet Mail was devised and used briefly. Both of those formats Internet Mail was devised and used briefly. Both of those formats
are completely obsolete; they are documented in Appendix A.1 and are completely obsolete; they are documented in Appendix A.1 and
Appendix A.2 for historical reasons only. With publication of [RFC Appendix A.2 for historical reasons only. With publication of [RFC
850] in 1983, news articles came to closely resemble Internet Mail 850] in 1983, news articles came to closely resemble Internet Mail
messages, with some restrictions and some additional headers. [RFC messages, with some restrictions and some additional header fields.
1036] in 1987 updated [RFC 850] without making major changes. [RFC 1036] in 1987 updated [RFC 850] without making major changes.
A Draft popularly referred to as "Son of 1036" [Son-of-1036] was A Draft popularly referred to as "Son of 1036" [Son-of-1036] was
written in 1994 by Henry Spencer. Much is taken directly from Son of written in 1994 by Henry Spencer. Much is taken directly from Son of
1036, and it is hoped that we have followed its spirit and 1036, and it is hoped that we have followed its spirit and
intentions. intentions.
[It is anticipated that [Son-of-1036] will shortly be published as an [It is anticipated that [Son-of-1036] will shortly be published as an
informational RFC (for purposes of historical documentation only), in informational RFC (for purposes of historical documentation only), in
which case most historical information can be removed from this draft, which case most historical information can be removed from this draft,
including the whole of Appendix A.1 and Appendix A.2.] including the whole of Appendix A.1 and Appendix A.2.]
News Article Architecture and Protocols February 2005 News Article Architecture and Protocols July 2005
2. Definitions, Notations and Conventions 2. Definitions, Notations and Conventions
2.1. Definitions 2.1. Definitions
An "article" is the unit of news, synonymous with an [RFC 2822] An "article" is the unit of news, synonymous with an [RFC 2822]
"message". A "proto-article" (7.2.1) is one that has been created by "message". A "proto-article" is one that has not yet been injected
a "posting agent" but has not yet been injected into a Netnews system into the news system. In constrast to an article, a proto- article
system by an "injecting agent". It may lack some otherwise mandatory may lack some mandatory header fields
headers.
A "message identifier" (F-3.1.3) is a unique identifier for an A "message identifier" (F-3.1.3) is a unique identifier for an
article, usually supplied by the posting agent which posted it or, article, usually supplied by the posting agent which posted it or,
failing that, by the injecting agent. It distinguishes the article failing that, by the injecting agent. It distinguishes the article
from every other article ever posted anywhere. Articles with the same from every other article ever posted anywhere. Articles with the same
message identifier are treated as if they are the same article message identifier are treated as if they are the same article
regardless of any differences in the body or headers. regardless of any differences in the body or header fields.
A "newsgroup" is a single news forum, a logical bulletin board, A "newsgroup" is a single news forum, a logical bulletin board,
having a name and nominally intended for articles on a specific having a name and nominally intended for articles on a specific
topic. An article is "posted to" a single newsgroup or several topic. An article is "posted to" a single newsgroup or several
newsgroups. When an article is posted to more than one newsgroup, it newsgroups. When an article is posted to more than one newsgroup, it
is said to be "crossposted"; note that this differs from posting the is said to be "crossposted"; note that this differs from posting the
same text as part of each of several articles, one per newsgroup. same text as part of each of several articles, one per newsgroup.
A newsgroup may be "moderated", in which case submissions are not A newsgroup may be "moderated", in which case submissions are not
posted directly, but mailed to a "moderator" for consideration and posted directly, but mailed to a "moderator" for consideration and
possible posting. Moderators are typically human but may be possible posting. Moderators are typically human but may be
implemented partially or entirely in software. implemented partially or entirely in software.
A "hierarchy" is the set of all newsgroups whose names share a first A "hierarchy" is the set of all newsgroups whose names share a first
component (as defined in F-3.1.5). The term "sub-hierarchy" is also component (as defined in F-3.1.5). The term "sub-hierarchy" is also
used where several initial components are shared. used where several initial components are shared.
A "poster" is the person or software that composes a possibly A "poster" is the person or software that composes and submits a
compliant article for submission to a posting agent. The poster is possibly compliant article for submission to a posting agent. The
synonymous with [RFC 2822]'s author. poster is analogous to [RFC 2822]'s author.
A "reader" is the person or software reading news articles. A "reader" is the person or software reading news articles.
[Alternative-1.]
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. an earlier article, its "precursor". Every followup includes a
References header field identifying that precursor (but note that
An article is a "precursor" of some later article which is a followup non-followup articles may also use a References header field).
to it, or which is otherwise intended to be grouped with it for
purposes of display (e.g. as a part of a multipart posting such as a
FAQ).
[Alternative-2.]
A "followup" to an earlier article (its "precursor") is one intended
to be grouped with that article for purposes of display (e.g. because
it is a response to its contents or is a part of a multipart posting
News Article Architecture and Protocols February 2005
such as a FAQ).
[End of alternatives]
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.
A "sender" is the person or software (usually, but not always, the A "sender" is the person or software (usually, but not always, the
same as the poster) responsible for the operation of the posting same as the poster) responsible for the operation of the posting
agent or, which amounts to the same thing, for passing the article to agent or, which amounts to the same thing, for passing the article to
the injecting agent. the injecting agent.
[Is the definition in RFC 2822 sufficient?] [Is the definition in RFC 2822 sufficient?]
News Article Architecture and Protocols July 2005
A "control message" is an article which is marked as containing A "control message" is an article which is marked as containing
control information; a "serving agent" (and in some cases a "relaying control information; a "serving agent" (and in some cases a "relaying
agent") receiving such an article may (subject to the policies agent") receiving such an article may (subject to the policies
observed at that site) take actions beyond just filing and passing on observed at that site) take actions beyond just filing and passing on
the article. the article.
The "semantic content" (often abbreviated to just "content" when the
context is clear) of a header field is its semantic interpretation;
i.e. what remains after unfolding it and removing its field name with
its colon and any leading and trailing whitespace and, in the case of
structured header fields only, ignoring comments and other
semantically invisible items and replacing white space by a single
SP.
2.2. Defining the Architecture 2.2. Defining the Architecture
A Netnews system is a distributed database composed of "agents" of A Netnews system is a distributed database composed of "agents" of
various types which, acting together according to the protocols various types which, acting together according to the protocols
defined in section 7 of this standard, causes articles to be defined in section 7 of this standard, causes articles to be
propagated throughout the system and to be made available to its propagated throughout the system and to be made available to its
readers. The protocols ensure that all copies of a given article, readers. The protocols ensure that all copies of a given article,
wherever stored, are identical apart from those headers defined as wherever stored, are identical apart from those header fields defined
variant (2.3). as variant (2.4).
A "posting agent" is the software that assists posters to prepare A "posting agent" is the software that assists posters to prepare
proto-articles in compliance with [USEFOR]. The proto-article is proto-articles in compliance with [USEFOR]. The proto-article is
then passed on to an "injecting agent" for final checking and then passed on to an "injecting agent" for final checking and
injection into the news stream. If the article is not compliant, or injection into the news stream. If the article is not compliant, or
is rejected by the injecting agent, then the posting agent informs is rejected by the injecting agent, then the posting agent informs
the poster with an explanation of the error. the poster with an explanation of the error.
A "reading agent" is software which presents articles to a reader. A "reading agent" is software which presents articles to a reader.
[Alternative-1.]
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.
[Alternative-2.]
A "followup agent" is a combination of reading agent and posting
agent that aids in the preparation and posting of an article which is
a response to some precursor.
[End of alternatives]
An "injecting agent" takes the finished article from the posting An "injecting agent" takes the finished article from the posting
agent (often via the NNTP "POST" command), performs some final checks agent (often via the NNTP "POST" command), performs some final checks
and passes it on to a "relaying agent" for general distribution. It and passes it on to a "relaying agent" for general distribution.
is expected to bear some responsibility towards the rest of the
News Article Architecture and Protocols February 2005
network for the behaviour of its posters (and provision is therefore
made for it to be easily contactable by email).
[That provision is expected to go into USEFOR.]
A "relaying agent" is software which receives allegedly compliant A "relaying agent" is software which receives allegedly compliant
articles from injecting agents and/or other relaying agents, and articles from injecting agents and/or other relaying agents, and
possibly passes copies on to other relaying agents and "serving possibly passes copies on to other relaying agents and "serving
agents". agents".
A "serving agent" receives an article from a relaying agent and files A "serving agent" receives an article from a relaying agent and files
it in a "news database". It also provides an interface for reading it in a "news database". It also provides an interface for reading
agents to access the news database. agents to access the news database.
A "news database" is the set of articles and related structural A "news database" is the set of articles and related structural
information stored by a serving agent and made available for access information stored by a serving agent and made available for access
by reading agents. by reading agents.
News Article Architecture and Protocols July 2005
A "gateway" is software which receives news articles and converts A "gateway" is software which receives news articles and converts
them to messages of some other kind (e.g. mail to a mailing list), or them to messages of some other kind (e.g. mail to a mailing list), or
vice versa; in essence it is a translating relaying agent that vice versa; in essence it is a translating relaying agent that
straddles boundaries between different methods of message exchange. straddles boundaries between different methods of message exchange.
The most common type of gateway connects newsgroup(s) to mailing The most common type of gateway connects newsgroup(s) to mailing
list(s), either unidirectionally or bidirectionally, but there are list(s), either unidirectionally or bidirectionally, but there are
also gateways between news networks using the [USEFOR] news format also gateways between news networks using the [USEFOR] news format
and those using other formats. and those using other formats.
Posting, reading and followup agents (which are usually just Posting, reading and followup agents (which are usually just
different services provided by the same piece of software) are known different services provided by the same piece of software) are known
collectively as "user agents". collectively as "user agents".
2.3. Variant Headers Injecting, relaying and serving agents (which are often just
different services provided by the same piece of software) are known
collectively as "news-servers".
Headers with the variant property may differ between (or even be 2.3. Identification of news-servers
completely absent from) copies of the same article as stored or
News-servers need to identify themselves by inserting their public
name, in the form of a <path-identity> (F-3.1.6), into Path,
Injection-Info and Xref header fields. An injecting agent MUST
identify itself with the same <path-identity> in both Path and
Injection-Info header fields, and a serving agent SHOULD use the same
<path-identity> in both Path and Xref header fields.
The following possibilities are available when choosing a <path-
identity>, but some of them are less suited to providing a unique
identity for the news-server concerned and are NOT RECOMMENDED, as
shown:
1. A fully qualified domain name (FQDN) associated with an "A" or
"AAAA" record (or an equivalent "CNAME"), which SHOULD identify
the actual host inserting this <path-identity> and, ideally,
should also be "mailable" (see below).
2. An encoding of an IP address - <IPv4address> or <IPv6address> [RFC
3986] - which SHOULD be a publicly recognized address [RFC 1918]
for the actual host, as above. This option SHOULD NOT be used if
an FQDN for that host is available.
3. A fully qualified domain name (FQDN) associated with an "MX"
record, which MUST be "mailable".
4. Some other (arbitrary) name believed to be unique and registered
at least with all other news-servers sending articles directly to
the given one. The news-server administrator is responsible for
choosing an appropriate name (and will bear the consequences of an
inappropriate choice). This option SHOULD NOT be used unless the
earlier options are unavailable (e.g. because the host in question
is not connected to the Internet), or unless it is of longstanding
usage and cessation would be unduly disruptive.
News Article Architecture and Protocols July 2005
NOTE: The syntax permits the colon character (which, prior to
this standard, was a <path-delimiter>) within any <path-
identity> which is in the form of an <IPv6address>. It would
therefor be unwise to choose, as such a name, anything composed
solely from four (or less) hexadecimal digits.
The FQDN of a news-server is "mailable" if its administrators can be
reached by email using both of the forms "usenet@" that FQDN and
"news@" that FQDN, in conformity with [RFC 2142].
For an injecting agent prepending to a Path header field (7.2.2), the
<path-identity> MUST be option 1 or 3 and the FQDN MUST be mailable,
and if the agent offers its services to the general public the form
"abuse@" that FQDN MUST also be available, unless a more specific
complaints address has been provided in a <complainto-param> of an
Injection-Info header field (F-3.2.14).
2.4. Variant Header Fields
Header fields with the variant property may differ between (or even
be completely absent from) copies of the same article as stored or
relayed throughout a Netnews system. The manner of the difference (or relayed throughout a Netnews system. The manner of the difference (or
absence) MUST be as specified in this (or some future) standard. absence) MUST be as specified in this (or some future) standard.
Typically, these headers are modified as articles are propagated, or Typically, these header fields are modified as articles are
they reflect the status of the article on a particular serving agent, propagated, or they reflect the status of the article on a particular
or cooperating group of such agents. A variant header MAY be placed serving agent, or cooperating group of such agents. A variant header
anywhere within the headers (though placing it first is recommended). field MAY be placed anywhere within the header fields (though placing
it first is recommended).
The following headers are classified as "variant": The following header fields are classified as "variant":
o Path (F-3.1.6) - augmented at each relaying agent that an article o Path (F-3.1.6) - augmented at each relaying agent that an article
passes through. passes through.
o Xref (F-3.2.10) - used to keep track of the <article-locator>s of o Xref (F-3.2.11) - used to keep track of the <article-locator>s of
crossposted articles so that reading agents serviced by a crossposted articles so that reading agents serviced by a
particular serving agent can mark such articles as read. particular serving agent can mark such articles as read.
o Injection-Info (F-3.2.13) is also considered variant in some o Injection-Info (F-3.2.14) is also considered variant in some
special situations involving reinjection (7.2 and 7.2.2). special situations involving reinjection (7.2 and 7.2.2).
News Article Architecture and Protocols February 2005 2.5. Textual Notations
2.4. 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.
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.
News Article Architecture and Protocols July 2005
"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].
US-ASCII is a 7 bit character set. Please note that this standard US-ASCII is a 7 bit character set. Please note that this standard
requires that all agents be 8 bit clean; that is, they must accept requires that all agents be 8 bit clean; that is, they must accept
and transmit data without changing or omitting the 8th bit. and transmit data without changing or omitting the 8th bit.
Certain words, when capitalized, are used to define the significance Certain words, when capitalized, are used to define the significance
of individual requirements. The key words "MUST", "REQUIRED", of individual requirements. The key words "MUST", "REQUIRED",
"SHOULD", "RECOMMENDED", "MAY" and "OPTIONAL", and any of those words "SHOULD", "RECOMMENDED", "MAY" and "OPTIONAL", and any of those words
associated with the word "NOT", are to be interpreted as described in associated with the word "NOT", are to be interpreted as described in
[RFC 2119]. [RFC 2119].
skipping to change at page 9, line 48 skipping to change at page 10, line 32
NOTE: A requirement imposed on a relaying or serving agent NOTE: A requirement imposed on a relaying or serving agent
regarding some particular article should be understood as regarding some particular article should be understood as
applying only if that article is actually accepted for applying only if that article is actually accepted for
processing (since any agent may always reject any article processing (since any agent may always reject any article
entirely, for reasons of site policy). entirely, for reasons of site policy).
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, header fields 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
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].
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
News Article Architecture and Protocols February 2005
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.
3.1. Principal Changes 3.1. Principal Changes
o The [RFC 2822] conventions for parenthesis-enclosed <comment>s in o The [RFC 2822] conventions for parenthesis-enclosed <comment>s in
headers are supported. header fields are supported in all newly defined header fields
o Whitespace is permitted in Newsgroups headers, permitting folding and in header fields inherited from [RFC 2822]. They are,
of such headers. Indeed, all headers can now be folded. however, still disallowed for performance and/or compatibility
o An enhanced syntax for the Path header enables the injection reasons in the Message-ID, Newsgroups, Path, Followup-To,
point of and the route taken by an article to be determined with Control, Supersedes, Distribution, Xref and Lines header fields.
certainty. o Whitespace is permitted in Newsgroups header fields, permitting
folding of such header fields. Indeed, all header fields can now
be folded.
News Article Architecture and Protocols July 2005
o An enhanced syntax for the Path header field enables the
injection point of and the route taken by an article to be
determined with certainty.
o MIME is recognized as an integral part of Netnews. o MIME is recognized as an integral part of 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 is a new mandatory Injection-Date header to facilitate the o There is a new mandatory Injection-Date header field to
rejection of stale articles. facilitate the rejection of stale articles.
o There are several new optional headers defined, notably Archive, o There are new optional header fields defined, Archive,
Complaints-To, Injection-Info, Mail-Copies-To, Posted-And-Mailed Injection-Info and User-Agent, leading to increased
and User-Agent, leading to increased functionality. functionality.
o Certain headers and Control messages (F-3.3 and Appendix A.3) o Certain header fields and Control messages (F-3.3 and Appendix
have been made obsolete. A.3) have been made obsolete.
o Distributions are expected to be checked at the receiving end, as o Distributions are expected to be checked at the receiving end, as
well as the sending end, of a relaying link. well as the sending end, of a relaying link.
o There are numerous other small changes, clarifications and o There are numerous other small changes, clarifications and
enhancements. enhancements.
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
skipping to change at page 10, line 56 skipping to change at page 11, line 45
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 user agents may continue to be used, been designed so that existing user 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 <comment>s in headers do not affect serving and o [RFC 2822] style <comment>s in header fields do not affect
relaying agents (note that the Message-ID, Newsgroups, serving and relaying agents. They are unlikely to hinder their
Distribution and Path headers do not contain them). They are proper display in existing reading agents except in the case of
unlikely to hinder their proper display in existing reading the References header field in agents which thread articles.
agents except in the case of the References header in agents Therefore, it is provided that they SHOULD NOT be generated in
that case.
o Because of its importance to all serving agents, the newly
permitted whitespace and folding in Newsgroups header fields
SHOULD NOT be generated (though it MUST be accepted); this
restriction may well be removed in a future version of this
standard.
o The new style of Path header field, using "!!" as a <path-
delimiter>, is already consistent with the previous standards.
However, the intention is that relaying agents should eventually
reject articles in the old style, and so this possibility should
be offered as a configurable option in relaying agents. User
News Article Architecture and Protocols February 2005 News Article Architecture and Protocols July 2005
which thread articles. Therefore, it is provided that they SHOULD agents are unaffected.
NOT be generated except where permitted by the previous
standards.
o Because of its importance to all serving agents, the extension
permitting whitespace and folding in Newsgroups headers SHOULD
NOT be used until it has been widely deployed amongst relaying
agents. User agents are unaffected.
o The new style of Path header is already consistent with the
previous standards. However, the intention is that relaying
agents should eventually reject articles in the old style, and so
this possibility should be offered as a configurable option in
relaying agents. User agents are unaffected.
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 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 Provision is made for relaying and serving agents to use the Date o Provision is made for relaying and serving agents to use the Date
header in the case of articles injected through existing agents header field in the case of articles injected through existing
which do not provide an Injection-Date header. agents which do not yet provide an Injection-Date header field.
o All the headers newly introduced by this standard can safely be o All the header fields newly introduced by this standard can
ignored by existing software, albeit with loss of the new safely be ignored by existing software, albeit with loss of the
functionality. new functionality.
4. Transport 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.
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).
News Article Architecture and Protocols February 2005
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.
In particular, transmission paths MUST convey all headers (including In particular, transmission paths MUST convey all header fields
body part headers and headers within message/rfc822 objects) intact, (including body part header fields and header fields within
even if they contain octets in the range 128 to 255. These message/rfc822 objects) intact, even if they contain octets in the
requirements include the transmissiom paths between posting agents, range 128 to 255. Furthermore, relaying agents MUST, and other
injecting agents, relaying agents, serving agents and reading agents, agents SHOULD, convey lines even if they exceed 998 characters in
but NOT the paths traversed by Netnews articles that have been length, especially in article bodies. These requirements include the
gatewayed into Email (7.9.1). transmissiom paths between posting agents, injecting agents, relaying
agents, serving agents and reading agents, but NOT the paths
News Article Architecture and Protocols July 2005
traversed by Netnews articles that have been gatewayed into Email
(7.9.1).
[At some point it will be necessary for the IMAP standards to catch up [At some point it will be necessary for the IMAP standards to catch up
with these requirements.] with these requirements.]
5. Definition of new Media Types 5. Definition of new Media Types
This standard defines (or redefines) several new Media Types, which This standard defines (or redefines) several new Media Types, which
require to be registered with IANA as provided for in [RFC 2048]. require to be registered with IANA as provided for in [RFC 2048].
5.1. Application/news-transmission 5.1. Application/news-transmission
The Media Type "application/news-transmission" is intended for the The Media Type "application/news-transmission" is intended for the
encapsulation of complete news articles where the intention is that encapsulation of complete news articles where the intention is that
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 7.2.2) and it is also the preferred method when sending to an (see 7.2.2) and it is also the preferred method when sending to an
email-to-news gateway (see 7.9.2). email-to-news gateway (see 7.9.2).
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 header fields and it
a convenient way of "tunnelling" a news article through a provides a convenient way of "tunnelling" a news article through
transport medium that does not support 8bit characters. a transport medium that does not support 8bit characters.
The MIME Media Type definition of "application/news-transmission" is: The MIME Media Type definition of "application/news-transmission" 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
usage=inject usage=inject
usage=relay usage=relay
Encoding considerations: A transfer-encoding (such as Quoted- Encoding considerations: A transfer-encoding (such as Quoted-
skipping to change at page 13, line 4 skipping to change at page 13, line 51
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
host's system beyond just storage of the host's system beyond just storage of the
article. However, such control messages article. However, such control messages
also occur in normal news flow, so most also occur in normal news flow, so most
hosts will already be suitably defended hosts will already be suitably defended
News Article Architecture and Protocols February 2005
against undesired effects. against undesired effects.
Published specification: [USEPRO] Published specification: [USEPRO]
Body part: A complete article or proto-article, ready Body part: A complete article or proto-article, ready
for injection into Netnews, or a batch of for injection into Netnews, or a batch of
such articles in the batch format described such articles in the batch format described
in section 6.4. in section 6.4.
NOTE: It is likely that the recipient of an "application/news- NOTE: It is likely that the recipient of an "application/news-
transmission" will be a specialized gateway (e.g. a moderator's transmission" will be a specialized gateway (e.g. a moderator's
submission address) able to accept articles with only one of the submission address) able to accept articles with only one of the
News Article Architecture and Protocols July 2005
three usage parameters "moderate", "inject" and "relay", hence three usage parameters "moderate", "inject" and "relay", hence
the reason why they are optional, being redundant in most the reason why they are optional, being redundant in most
situations. Nevertheless, they MAY be used to signify the situations. Nevertheless, they MAY be used to signify the
originator's intention with regard to the transmission, so originator's intention with regard to the transmission, so
removing any possible doubt. removing any possible doubt.
When the parameter "relay" is used, or implied, the body part MAY be When the parameter "relay" is used, or implied, the body part MAY be
a batch of articles to be transmitted together, in which case the a batch of articles to be transmitted together, in which case the
batch format defined in section 6.4 MUST be used. batch format defined in section 6.4 MUST be used.
skipping to change at page 14, line 4 skipping to change at page 14, line 51
The MIME Media Type definition of "application/news-groupinfo" is: The MIME Media 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
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
News Article Architecture and Protocols February 2005
of a control message for the creation or of a control message for the creation or
modification of a Netnews newsgroup modification of a Netnews newsgroup
Published specification: [USEPRO] Published specification: [USEPRO]
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
News Article Architecture and Protocols July 2005
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
%x66.69.6C.65.3A %x66.69.6C.65.3A
; case sensitive ; case sensitive
; "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 )
skipping to change at page 15, line 4 skipping to change at page 15, line 52
with the "checkgroups" control message (6.2.4). It MUST NOT be used with the "checkgroups" control message (6.2.4). It MUST NOT be used
except as a part of such control messages. except as a part of such control messages.
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 (sub)hierarchy, their <newsgroup- of all the newsgroups in a (sub)hierarchy, their <newsgroup-
description>s and their moderation status. description>s and their moderation status.
The MIME Media Type definition of "application/news-checkgroups" is: The MIME Media Type definition of "application/news-checkgroups" is:
MIME type name: application MIME type name: application
News Article Architecture and Protocols February 2005
MIME subtype name: news-checkgroups MIME subtype name: news-checkgroups
Required parameters: none Required parameters: none
Disposition: by default, inline Disposition: by default, inline
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
Published specification: [USEPRO] Published specification: [USEPRO]
News Article Architecture and Protocols July 2005
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 5.3 valid-group = newsgroups-line ; see 5.3
6. Control Messages 6. Control Messages
The following sections document the control messages. "Message" is The following sections document the control messages. "Message" is
used herein as a synonym for "article" unless context indicates used herein as a synonym for "article" unless context indicates
otherwise. otherwise.
Each <control-command> comprises a <verb>, which indicates the action Each <control-command> comprises a <verb>, which indicates the action
to be taken, and <argument>(s), which supply the details (see F- to be taken, and <argument>(s), which supply the details (see F-
3.2.4). The following sections contain syntactic definitions for the 3.2.5). The following sections contain syntactic definitions for the
<verb>, <argument>s, and possibly the body, for each type of control <verb>, <argument>s, and possibly the body, for each type of control
message. message.
[The term <control-command> is now used to denote the syntactic object [The term <control-command> is now used to denote the syntactic object
within the Control header, to distinguish it from "control message", within the Control header field, to distinguish it from "control
which refers to the whole article.] message", which refers to the whole article.]
The Newsgroups header of each control message SHOULD include the The Newsgroups header field of each control message SHOULD include
<newsgroup-name>(s) for the group(s) affected (i.e. groups to be the <newsgroup-name>(s) for the group(s) affected (i.e. groups to be
created, modified or removed, or containing articles to be canceled). created, modified or removed, or containing articles to be canceled).
This is to ensure that the message propagates to all sites which This is to ensure that the message propagates to all sites which
receive (or would receive) that group(s). It MAY include other receive (or would receive) that group(s). It MAY include other
<newsgroup-name>s so as to improve propagation (but this practice may <newsgroup-name>s so as to improve propagation (but this practice may
cause the control message to propagate also to places where it is cause the control message to propagate also to places where it is
unwanted, or even cause it not to propagate where it should, so it unwanted, or even cause it not to propagate where it should, so it
should not be used without good reason). should not be used without good reason).
NOTE: Propagation is controlled by relaying agents, and it may NOTE: Propagation is controlled by relaying agents, and it may
be necessary for relaying agents to take special steps to ensure be necessary for relaying agents to take special steps to ensure
that control messages such as newgroup messages for not-yet- that control messages such as newgroup messages for not-yet-
existent newsgroups are propagated correctly (see 7.3). existent newsgroups are propagated correctly (see 7.3).
The presence of a Subject header whose content starts with the string The presence of a Subject header field whose content starts with the
"cmsg " followed by a <control-command> was construed under [RFC string "cmsg " followed by a <control-command> was construed under
1036] as a request to perform that control action (even if no genuine [RFC 1036] as a request to perform that control action (even if no
Control header was present). Indeed, some implementations went genuine Control header field was present). Indeed, some
further and added the implied Control header before injecting. implementations went further and added the implied Control header
Likewise, the presence of a <newsgroup-name> ending in ".ctl" in the field before injecting. Likewise, the presence of a <newsgroup-name>
Newsgroups header caused the Subject header content (not starting ending in ".ctl" in the Newsgroups header field caused the Subject
with "cmsg" in this case) to be interpreted as a <control-command>. header field content (not starting with "cmsg" in this case) to be
interpreted as a <control-command>.
News Article Architecture and Protocols February 2005 All these practices, which have already largely fallen into disuse,
are now declared to be Obsolete, and Subject header fields MUST NOT
now be interpreted as <control-command>s under any circumstances.
All these practices are now declared to be Obsolete, and Subject [Possible addtional text:]
headers MUST NOT now be interpreted as <control-command>s under any
circumstances. News Article Architecture and Protocols July 2005
In order to prevent continuing interpretation of Subject header
fields in this way by existing agents, posting and injecting agents
SHOULD detect and decline to post articles in which the Subject
header field starts with the word "cmsg" and in which there is no
Control header field.
The descriptions below set out REQUIREMENTS to be followed by sites The descriptions below set out REQUIREMENTS to be followed by sites
that receive control messages and choose to honour them. However, that receive control messages and choose to honour them. However,
nothing in these descriptions should be taken as overriding the right nothing in these descriptions should be taken as overriding the right
of any such site, in accordance with its local policy, to refuse to of any such site, in accordance with its local policy, to refuse to
honour any particular control message, or to refer it to an honour any particular control message, or to refer it to an
administrator for approval (either as a class or on a case-by-case administrator for approval (either as a class or on a case-by-case
basis). basis).
6.1. Digital Signature of Headers 6.1. Digital Signature of Header Fields
It is most desirable that group control messages (6.2) in particular It is most desirable that group control messages (6.2) 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 header fields closely associated with
(including at least the Approved, Message-ID and Date headers). At them (including at least Approved, Message-ID and Date). At the time
the time of writing, this is usually done by means of a protocol of writing, this is usually done by means of a protocol known as
known as "PGPverify" ([PGPVERIFY]), and continued usage of this is "PGPverify" ([PGPVERIFY]), and continued usage of this is encouraged
encouraged at least as an interim measure. 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, header fields. That
would also address other Netnews security issues. extension would also address other Netnews security issues.
6.2. Group Control Messages 6.2. Group Control Messages
"Group control messages" are the sub-class of control messages that "Group control messages" are the sub-class of control messages that
request some update to the configuration of the groups known to a request some update to the configuration of the groups known to a
serving agent, namely "newgroup", "rmgroup", "mvgroup" and serving agent, namely "newgroup", "rmgroup", "mvgroup" and
"checkgroups", plus any others created by extensions to this "checkgroups", plus any others created by extensions to this
standard. standard.
All of the group control messages MUST have an Approved header Group control messages that attempt to create groups with names that
(F-3.2.8) which, in those hierarchies where appropriate are deprecated or reserved according to F-3.1.5 MUST NOT be issued,
except by prior agreement within some cooperating subnet. Moreover,
sites receiving such control messages SHOULD check them for
conformance before honouring them.
All of the group control messages MUST have an Approved header field
(F-3.2.9) which, in those hierarchies where appropriate
administrative agencies exist (see 1.1), identifies the appropriate administrative agencies exist (see 1.1), identifies the appropriate
person or entity as authorized by those agencies. The authorized person or entity as authorized by those agencies. The authorized
person or entity SHOULD adhere to the conventions and restrictions on person or entity SHOULD adhere to any conventions and restrictions on
the format of <newsgroup-name>s established for those hierarchies the format of <newsgroup-name>s established for those hierarchies
(see F-3.1.5). [USEAGE].
[But that reference presumes some changes in the current USEFOR.]
News Article Architecture and Protocols July 2005
6.2.1. The 'newgroup' Control Message 6.2.1. The 'newgroup' Control Message
control-command =/ Newgroup-command control-command =/ Newgroup-command
Newgroup-command = "newgroup" Newgroup-arguments Newgroup-command = "newgroup" Newgroup-arguments
Newgroup-arguments = CFWS newsgroup-name [ CFWS newgroup-flag ] Newgroup-arguments = FWS newsgroup-name [ FWS newgroup-flag ]
newgroup-flag = "moderated" newgroup-flag = "moderated"
News Article Architecture and Protocols February 2005
The "newgroup" control message requests that the specified group be The "newgroup" control message requests that the specified group be
created or have its moderation status or <newsgroups-line> changed. created or have its moderation status or <newsgroups-line> changed.
When the request is honoured, if the <newgroup-flag> "moderated" is When the request is honoured, if the <newgroup-flag> "moderated" is
present then the status of the group SHOULD be marked as moderated, present then the status of the group SHOULD be marked as moderated,
and vice versa. "Moderated" is the only such flag defined by this and vice versa. "Moderated" is the only such flag defined by this
standard; other flags MAY be defined for use in cooperating subnets, standard; other flags MAY be defined for use in cooperating subnets,
but newgroup messages containing them MUST NOT be acted on outside of but newgroup messages containing them MUST NOT be acted on outside of
those subnets. those subnets.
NOTE: Specifically, some alternative flags such as "y" and "m", NOTE: Specifically, some alternative flags such as "y" and "m",
skipping to change at page 17, line 42 skipping to change at page 18, line 49
maintained by the serving agent. maintained by the serving agent.
2. Other parts containing useful information about the background of 2. Other parts containing useful information about the background of
the newgroup message (typically of type "text/plain"). the newgroup message (typically of type "text/plain").
3. Parts containing initial articles for the newsgroup. See section 3. Parts containing initial articles for the newsgroup. See section
6.2.1.2 for details. 6.2.1.2 for details.
In the event that there is only the single (i.e. application/news- In the event that there is only the single (i.e. application/news-
groupinfo) subpart present, it will suffice to include a "Content- groupinfo) subpart present, it will suffice to include a "Content-
Type: application/news-groupinfo" amongst the headers of the control Type: application/news-groupinfo" amongst the header fields of the
message. Otherwise, a "Content-Type: multipart/mixed" header will be control message. Otherwise, a "Content-Type: multipart/mixed" header
needed, and each separate part will then need its own Content-Type field will be needed, and each separate part will then need its own
header. Content-Type header field.
6.2.1.2. Initial Articles 6.2.1.2. 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 as soon as it has been created or modified. These parts are newsgroup as soon as it has been created or modified. These parts are
identified by having the Media Type "application/news-transmission", identified by having the Media Type "application/news-transmission",
possibly with the parameter "usage=inject". The body of each such possibly with the parameter "usage=inject". The body of each such
News Article Architecture and Protocols July 2005
part should be a complete proto-article, ready for posting. This part should be a complete proto-article, ready for posting. This
feature is intended for the posting of charters, initial FAQs and the feature is intended for the posting of charters, initial FAQs and the
like to the newly formed group. like to the newly formed group.
The Newsgroups header of the proto-article MUST include the The Newsgroups header field of the proto-article MUST include the
<newsgroup-name> of the newly created or modified group. It MAY <newsgroup-name> of the newly created or modified group. It MAY
include other <newsgroup-name>s. If the proto-article includes a include other <newsgroup-name>s. If the proto-article includes a
Message-ID header field, the message identifier in it MUST be
News Article Architecture and Protocols February 2005 different from that of any existing article and from that of the
control message as a whole. Alternatively such a message identifier
Message-ID header, the message identifier in it MUST be different MAY be derived by the injecting agent when the proto-article is
from that of any existing article and from that of the control posted. The proto-article SHOULD include the header field
message as a whole. Alternatively such a message identifier MAY be "Distribution: local".
derived by the injecting agent when the proto-article is posted. The
proto-article SHOULD include the header "Distribution: local".
The proto-article SHOULD be injected at the serving agent that The proto-article SHOULD be injected at the serving agent that
processes the control message AFTER the newsgroup in question has processes the control message AFTER the newsgroup in question has
been created or modified. It MUST NOT be injected if the newsgroup been created or modified. It MUST NOT be injected if the newsgroup
is not, in fact, created (for whatever reason). It MUST NOT be is not, in fact, created (for whatever reason). It MUST NOT be
submitted to any relaying agent for transmission beyond the serving submitted to any relaying agent for transmission beyond the serving
agent(s) upon which the newsgroup creation has just been effected (in agent(s) upon which the newsgroup creation has just been effected (in
other words, it is to be treated as having a "Distribution: local" other words, it is to be treated as having a "Distribution: local"
header, whether such a header is actually present or not). header field, whether such a field is actually present or not).
NOTE: It is not precluded that the proto-article is itself a NOTE: It is not precluded that the proto-article is itself a
control message or other type of special article, to be control message or other type of special article, to be
activated only upon creation of the new newsgroup. However, activated only upon creation of the new newsgroup. However,
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.
6.2.1.3. Example 6.2.1.3. Example
skipping to change at page 18, line 49 skipping to change at page 20, line 4
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
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:
News Article Architecture and Protocols July 2005
example.admin.info About the example.* groups (Moderated) example.admin.info About the example.* groups (Moderated)
--nxtprt --nxtprt
Content-Type: application/news-transmission Content-Type: application/news-transmission
Newsgroups: example.admin.info Newsgroups: example.admin.info
From: "example.all Administrator" <admin@noc.example> From: "example.all Administrator" <admin@noc.example>
Subject: Charter for example.admin.info Subject: Charter for example.admin.info
Message-ID: <charter-example.admin.info-20020227@noc.example> Message-ID: <charter-example.admin.info-20020227@noc.example>
Distribution: local Distribution: local
News Article Architecture and Protocols February 2005
Content-Type: text/plain; charset=us-ascii Content-Type: text/plain; charset=us-ascii
Content-Transfer-Encoding: 7bit Content-Transfer-Encoding: 7bit
The group example.admin.info contains regularly posted The group example.admin.info contains regularly posted
information on the example.* hierarchy. information on the example.* hierarchy.
--nxtprt-- --nxtprt--
6.2.2. The 'rmgroup' Control Message 6.2.2. The 'rmgroup' Control Message
control-command =/ Rmgroup-command control-command =/ Rmgroup-command
Rmgroup-command = "rmgroup" Rmgroup-arguments Rmgroup-command = "rmgroup" Rmgroup-arguments
Rmgroup-arguments = CFWS newsgroup-name Rmgroup-arguments = FWS newsgroup-name
The "rmgroup" control message requests that the specified group be The "rmgroup" control message requests that the specified group be
removed from the list of valid groups. The Media Type of the body is removed from the list of valid groups. The Media Type of the body is
unspecified; it MAY contain anything, usually an explanatory text. unspecified; it MAY contain anything, usually an explanatory text.
NOTE: It is entirely proper for a serving agent to retain the NOTE: It is entirely proper for a serving agent to retain the
group until all the articles in it have expired, provided that group until all the articles in it have expired, provided that
it ceases to accept new articles. it ceases to accept new articles.
6.2.2.1. Example 6.2.2.1. Example
skipping to change at page 19, line 46 skipping to change at page 20, line 56
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.
6.2.3. The 'mvgroup' Control Message 6.2.3. The 'mvgroup' Control Message
control-command =/ Mvgroup-command control-command =/ Mvgroup-command
Mvgroup-command = "mvgroup" Mvgroup-arguments Mvgroup-command = "mvgroup" Mvgroup-arguments
Mvgroup-arguments = CFWS newsgroup-name CFWS newsgroup-name Mvgroup-arguments = FWS newsgroup-name FWS newsgroup-name
[ CFWS newgroup-flag ] [ FWS newgroup-flag ]
News Article Architecture and Protocols July 2005
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 message body contains an "application/news-groupinfo" part (5.3) The message body contains an "application/news-groupinfo" part (5.3)
containing machine- and human-readable information about the new containing machine- and human-readable information about the new
group, and possibly other subparts as for a "newgroup" control group, and possibly other subparts as for a "newgroup" control
message. The information conveyed in the "application/news-groupinfo" message. The information conveyed in the "application/news-groupinfo"
body part, notably its <newsgroups-line> (5.3), is applied to the new body part, notably its <newsgroups-line> (5.3), is applied to the new
group. group.
News Article Architecture and Protocols February 2005
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 SHOULD in not exist already) as for a "newgroup" control message, and SHOULD in
any case be made moderated if a <newgroup-flag> "moderated" is any case be made moderated if a <newgroup-flag> "moderated" is
present, and vice versa. At the same time, arrangements SHOULD be present, and vice versa. At the same time, arrangements SHOULD be
made to remove the old group (as with a "rmgroup" control message), made to remove the old group (as with a "rmgroup" control message),
but only after a suitable overlap period to allow the network to but only after a suitable overlap period to allow the network to
adjust to the new arrangement. adjust to the 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
injecting agents associated with that serving agent SHOULD inhibit injecting agents associated with that serving agent SHOULD inhibit
skipping to change at page 20, line 48 skipping to change at page 22, line 4
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.
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
News Article Architecture and Protocols July 2005
their Newsgroups header fields 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
(F-3.2.10) MAY contain entries for either group (or even both). field (F-3.2.11) MAY contain entries for either group (or even both).
NOTE: Some serving agents that use an "active" file permit an NOTE: Some serving agents that use an "active" file permit an
entry of the form "oldgroup xxx yyy =newgroup", which enables entry of the form "oldgroup xxx yyy =newgroup", which enables
any articles arriving for oldgroup to be diverted to newgroup, any articles arriving for oldgroup to be diverted to newgroup,
thus providing a simple implementation of this feature. However, thus providing a simple implementation of this feature. However,
it is known that not all current serving agents will find it is known that not all current serving agents will find
implementation so easy (especially in the short term) which is implementation so easy (especially in the short term) which is
why it is not mandated by this standard. Nevertheless, its why it is not mandated by this standard. Nevertheless, its
eventual implementation in all serving agents is to be eventual implementation in all serving agents is to be
considered highly desirable. considered highly desirable.
News Article Architecture and Protocols February 2005
On the other hand, it is recognized that this feature would On the other hand, it is recognized that this feature would
likely not be implementable if the new group was already in likely not be implementable if the new group was already in
existence with existing articles in it. This situation should existence with existing articles in it. This situation should
not normally arise except when there is already some confusion not normally arise except when there is already some confusion
as to which groups are, or are not, supposed to exist in that as to which groups are, or are not, supposed to exist in that
hierarchy. Note that the "mvgroup" control message is not really hierarchy. Note that the "mvgroup" control message is not really
intended to be used for merging two existing groups. intended to be used for merging two existing groups.
6.2.3.1. Example 6.2.3.1. Example
skipping to change at page 21, line 47 skipping to change at page 23, line 4
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
Content-Type: application/news-transmission Content-Type: application/news-transmission
Newsgroups: example.admin.info Newsgroups: example.admin.info
From: "example.all Administrator" <admin@noc.example> From: "example.all Administrator" <admin@noc.example>
Subject: Charter for example.newgroup Subject: Charter for example.newgroup
Message-ID: <mvgroup-example.newgroup-20020430@noc.example> Message-ID: <mvgroup-example.newgroup-20020430@noc.example>
News Article Architecture and Protocols July 2005
Distribution: local Distribution: local
Content-Type: text/plain; charset=us-ascii Content-Type: text/plain; charset=us-ascii
Content-Transfer-Encoding: 7bit Content-Transfer-Encoding: 7bit
This group (formerly known as example.oldgroup) is for the This group (formerly known as example.oldgroup) is for the
discussion of examples. discussion of examples.
--nxt-- --nxt--
6.2.4. The 'checkgroups' Control Message 6.2.4. 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.
News Article Architecture and Protocols February 2005
control-command =/ Checkgroup-command control-command =/ Checkgroup-command
Checkgroup-command = "checkgroups" Checkgroup-arguments Checkgroup-command = "checkgroups" Checkgroup-arguments
Checkgroup-arguments= [ chkscope ] [ chksernr ] Checkgroup-arguments= [ chkscope ] [ chksernr ]
chkscope = 1*( CFWS ["!"] newsgroup-name ) chkscope = 1*( FWS ["!"] newsgroup-name )
chksernr = CFWS "#" 1*DIGIT chksernr = FWS "#" 1*DIGIT
A "checkgroups" message applies to any (sub-)hierarchy with a prefix A "checkgroups" message applies to any (sub-)hierarchy with a prefix
listed in the <chkscope> argument, provided that the rightmost listed in the <chkscope> argument, provided that the rightmost
matching <newsgroup-name> in the list is not immediately preceded by matching <newsgroup-name> in the list is not immediately preceded by
a "!". If no <chkscope> argument is given, it applies to all a "!". If no <chkscope> argument is given, it applies to all
hierarchies for which group statements appear in the body of the hierarchies for which group statements appear in the body of the
message. message.
NOTE: Some existing software does not support the <chkscope> NOTE: Some existing software does not support the <chkscope>
argument. Thus a "checkgroups" message SHOULD also contain the argument. Thus a "checkgroups" message SHOULD also contain the
groups of other subhierarchies the sender is not responsible groups of other subhierarchies the sender is not responsible
for. "New" software MUST ignore groups which do not fall within for. "New" software MUST ignore groups which do not fall within
the <chkscope> argument of the "checkgroups" message. the <chkscope> argument of the "checkgroups" message.
The <chksernr> argument is a serial number, which can be any positive The <chksernr> argument is a serial number, which can be any positive
integer (e.g. just numbered or the date in YYYYMMDD). It SHOULD integer (e.g. just numbered or the date in YYYYMMDD). It SHOULD
increase by an arbitrary value with every change to the group list increase by an arbitrary value with every change to the group list
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 field 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
of its 'de.alt.*' sub-hierarchy. of its 'de.alt.*' sub-hierarchy.
The body of the message has the Media Type "application/news- The body of the message has the Media Type "application/news-
checkgroups" (5.4). It asserts that the <valid-group>s it lists are checkgroups" (5.4). It asserts that the <valid-group>s it lists are
the only newsgroups in the specified hierarchies. the only newsgroups in the specified hierarchies.
News Article Architecture and Protocols July 2005
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-description>s, with the lists stored by other serving <newsgroup-description>s, 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.
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 '!' in the of an "invalidation" line beginning with a '!' in the
checkgroups-body is no longer provided by this standard. The checkgroups-body is no longer provided by this standard. The
intent of the feature was widely misunderstood and it was intent of the feature was widely misunderstood and it was
misused more often than it was used correctly. The same effect, misused more often than it was used correctly. The same effect,
if required, can now be obtained by the use of an appropriate if required, can now be obtained by the use of an appropriate
<chkscope> argument in conjunction with an empty <checkgroups- <chkscope> argument in conjunction with an empty <checkgroups-
body>. body>.
News Article Architecture and Protocols February 2005
6.3. Cancel 6.3. Cancel
The "cancel" message requests that a target article be "canceled", The "cancel" message requests that a target article be "canceled",
i.e. be withdrawn from circulation or access. i.e. be withdrawn from circulation or access.
control-command =/ Cancel-command control-command =/ Cancel-command
Cancel-command = "cancel" Cancel-arguments Cancel-command = "cancel" Cancel-arguments
Cancel-arguments = CFWS msg-id [CFWS] Cancel-arguments = FWS msg-id [FWS]
The argument identifies the article to be cancelled by its message The argument identifies the article to be cancelled by its message
identifier. The body SHOULD contain an indication of why the identifier. The body SHOULD contain an indication of why the
cancellation was requested. The "cancel" message SHOULD be posted to cancellation was requested. The "cancel" message SHOULD be posted to
the same newsgroup(s), with the same distribution(s), as the article the same newsgroup(s), with the same distribution(s), as the article
it is attempting to cancel. it is attempting to cancel.
A serving agent that elects to honour a "cancel" message SHOULD make A serving agent that elects to honour a "cancel" message SHOULD make
the article unavailable for relaying or serving (perhaps by deleting the article unavailable for relaying or serving (perhaps by deleting
it completely). If the target article is unavailable, and the it completely). If the target article is unavailable, and the
skipping to change at page 23, line 41 skipping to change at page 24, line 58
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 (i.e. those issued other digital signature of 3rd party cancels (i.e. those issued other
than by the sender, the moderator, or the injector). than by the sender, the moderator, or the injector).
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 (7.8). group, and it is up to that moderator to act upon it (7.8).
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 header fields of the "cancel" message should match those
original article has been removed from this standard, since it of the original article has been removed from this standard,
only encouraged cancel issuers to conceal their true identity,
and it was not usually checked or enforced by canceling News Article Architecture and Protocols July 2005
software. Therefore, both the From and/or Sender headers and
any Approved header should now relate to the entity responsible since it only encouraged cancel issuers to conceal their true
for issuing the "cancel" message. identity, and it was not usually checked or enforced by
canceling software. Therefore, both the From and/or Sender
header fields and any Approved header field should now relate to
the entity responsible for issuing the "cancel" message.
6.4. Ihave, sendme 6.4. 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
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.
News Article Architecture and Protocols February 2005
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-command =/ Ihave-command control-command =/ Ihave-command
Ihave-command = "ihave" Ihave-argument Ihave-command = "ihave" Ihave-argument
Ihave-argument = relayer-name Ihave-argument = relayer-name
control-command =/ Sendme-command control-command =/ Sendme-command
Sendme-command = "sendme" Sendme-argument Sendme-command = "sendme" Sendme-argument
Sendme-argument = Ihave-argument Sendme-argument = Ihave-argument
relayer-name = path-identity ; see a-5.6.1 relayer-name = path-identity ; see F-3.1.6
ihave-body = *( msg-id CRLF ) ihave-body = *( msg-id CRLF )
sendme-body = ihave-body sendme-body = ihave-body
The body of the message consists of a list of <msg-id>s, one per The body of the message consists of a list of <msg-id>s, one per
line. [RFC 1036] also permitted the list of <msg-id>s to appear in line. [RFC 1036] also permitted the list of <msg-id>s to appear in
the Ihave- or Sendme-argument with the syntax the Ihave- or Sendme-argument with the syntax
Ihave-argument = [FWS] *( msg-id FWS ) [relayer-name] Ihave-argument = [FWS] *( msg-id FWS ) [relayer-name]
but this form SHOULD NOT now be used, though relaying agents MAY but this form SHOULD NOT now be used, though relaying agents MAY
recognize and process it for backward compatibility. recognize and process it for backward compatibility.
skipping to change at page 24, line 43 skipping to change at page 26, line 5
articles having the specified message identifiers to the named articles having the specified message identifiers to the named
relaying agent. relaying agent.
Upon receipt of the sendme message, the receiving agent sends the Upon receipt of the sendme message, the receiving agent sends the
article(s) requested, often (especially when the transport protocol article(s) requested, often (especially when the transport protocol
is UUCP) in the form of one or more batches, each containing several is UUCP) in the form of one or more batches, each containing several
articles. The usual form of a <batch> is defined by the following articles. The usual form of a <batch> is defined by the following
syntax (which is also used in the application/news transmission media syntax (which is also used in the application/news transmission media
type (5.1)). type (5.1)).
News Article Architecture and Protocols July 2005
batch = 1*( batch-header article ) batch = 1*( batch-header article )
batch-header = "#!" SP rnews SP article-size CRLF batch-header = "#!" SP rnews SP article-size CRLF
rnews = %x72.6E.65.77.73 ; case sensitive "rnews" rnews = %x72.6E.65.77.73 ; case sensitive "rnews"
article-size = 1*DIGIT article-size = 1*DIGIT
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
disastrous. disastrous.
News Article Architecture and Protocols February 2005
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-name>s in the Newsgroups header point messages, by using <newsgroup-name>s in the Newsgroups header
of the form "to." followed by one (or possibly more) <component>s in field of the form "to." followed by one (or possibly more)
the form of a <relayer-name> (see section a-5.5.1 which forbids "to" <component>s in the form of a <relayer-name> (see section F-3.1.5
as the first <component> of a <newsgroup-name>). The control message which forbids "to" as the first <component> of a <newsgroup-name>).
SHOULD then be delivered ONLY to the relaying agent(s) identified by The control message SHOULD then be delivered ONLY to the relaying
that <relayer-name>, and any relaying agent receiving such a message agent(s) identified by that <relayer-name>, and any relaying agent
which includes its own <relayer-name> MUST NOT propagate it further. receiving such a message which includes its own <relayer-name> MUST
Each pair of relaying agent(s) sending and receiving these messages NOT propagate it further. Each pair of relaying agent(s) sending and
MUST be immediate neighbours, exchanging news directly with each receiving these messages MUST be immediate neighbours, exchanging
other. Each relaying agent advertises its new arrivals to the other news directly with each other. Each relaying agent advertises its new
using "ihave" messages, and each uses "sendme" messages to request arrivals to the other using "ihave" messages, and each uses "sendme"
the articles it lacks. messages to request the articles it lacks.
[Assumes forbidden newsgroup-names will be in USEFOR.]
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 identifiers. If ihave and sendme are being used to implement message identifiers. If ihave and sendme are being used to implement
a backup feed, it may be desirable to insert a delay between a backup feed, it may be desirable to insert a delay between
reception of an ihave and generation of a sendme, so that a slightly reception of an ihave and generation of a sendme, so that a slightly
slow primary feed will not cause large numbers of articles to be slow primary feed will not cause large numbers of articles to be
requested unnecessarily via sendme. requested unnecessarily via sendme.
6.5. Obsolete control messages. 6.5. Obsolete control messages.
skipping to change at page 25, line 46 skipping to change at page 27, line 4
version version
whogets whogets
senduuname senduuname
7. Duties of Various Agents 7. Duties of Various Agents
The following section sets out the duties of various agents involved The following section sets out the duties of various agents involved
in the creation, relaying and serving of Netnews articles. Insofar as in the creation, relaying and serving of Netnews articles. Insofar as
these duties are described as sequences of steps to be followed, it these duties are described as sequences of steps to be followed, it
should be understood that it is the effect of these sequences that is should be understood that it is the effect of these sequences that is
News Article Architecture and Protocols July 2005
important, and implementations may use any method that gives rise to important, and implementations may use any method that gives rise to
that same effect. that same effect.
In this section, the word "trusted", as applied to the source of some In this section, the word "trusted", as applied to the source of some
article, means that an agent processing that article has verified, by article, means that an agent processing that article has verified, by
some means, the identity of that source (which may be another agent some means, the identity of that source (which may be another agent
or a poster). or a poster).
NOTE: In many implementations, a single agent may perform NOTE: In many implementations, a single agent may perform
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.
News Article Architecture and Protocols February 2005
7.1. General principles to be followed 7.1. 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:
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
skipping to change at page 26, line 37 skipping to change at page 27, line 50
Cause no loops. Cause no loops.
7.2. Duties of an Injecting Agent 7.2. 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 (or other) agent and either forwarding it to a moderator or posting (or other) agent and either forwarding it to a moderator or
injecting it into the relaying system for access by readers. injecting it 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 [USEFOR]. that any article it injects conforms with the rules of [USEFOR]. It
is also expected to bear some responsibility towards the rest of the
network for the behaviour of its posters (and provision is therefore
made for it to be easily contactable by email).
In the normal course of events, an article that has already been In the normal course of events, an article that has already been
injected into a Netnews network will never pass through another injected into a Netnews network will never pass through another
injecting agent. So, if an injecting agent receives an otherwise injecting agent. So, if an injecting agent receives an otherwise
valid article that has already been injected (as evidenced by the valid article that has already been injected (as evidenced by the
presence of an Injection-Date header, an Injection-Info header, or presence of an Injection-Date header field, an Injection-Info header
more than one '%' <path-delimiter> in a Path header) it MAY choose to field, or more than one "POSTED" in a Path header field) it MAY
reject it, but otherwise SHOULD cause it to be relayed, as it stands,
by a relaying agent (7.3). News Article Architecture and Protocols July 2005
choose to reject it, but otherwise SHOULD cause it to be relayed, as
it stands, by a relaying agent (7.3).
In exceptional circumstances (e.g. as part of some complex gatewaying In exceptional circumstances (e.g. as part of some complex gatewaying
process, or where a relaying agent considers it essential for process, or where a relaying agent considers it essential for
fulfilling its responsibility towards the rest of the network) an fulfilling its responsibility towards the rest of the network) an
already injected article MAY be "reinjected" into the network. This already injected article MAY be "reinjected" into the network. This
standard does not prescribe any such circumstance; rather this is a standard does not prescribe any such circumstance; rather this is a
matter of policy to be determined by the administrators of each matter of policy to be determined by the administrators of each
injecting agent, who have the responsibility to ensure that no harm injecting agent, who have the responsibility to ensure that no harm
arises. In all other circumstances, unintented reinjection is to be arises. In all other circumstances, unintented reinjection is to be
avoided (see 7.9). Nevertheless, in order to preserve the integrity avoided (see 7.9). Nevertheless, in order to preserve the integrity
of the network in these special cases, this standard does set out the of the network in these special cases, this standard does set out the
correct way to reinject (see special provisions in 7.2.2 Steps 3, 4, correct way to reinject (see special provisions in 7.2.2 Steps 3, 4,
7 and 9). 7 and 9).
News Article Architecture and Protocols February 2005
It is usual for an injecting agent to be closely associated with a It is usual for an injecting agent to be closely associated with a
serving agent, thus giving it access to the list (7.4) showing the serving agent, thus giving it access to the list (7.4) showing the
moderation status of the newsgroups it is likely to handle. In the moderation status of the newsgroups it is likely to handle. In the
event that it does not have such an associated serving agent, it MUST event that it does not have such an associated serving agent, it MUST
maintain that list itself. maintain that list itself.
7.2.1. Proto-articles 7.2.1. Proto-articles
A proto-article SHOULD NOT be propagated in that form to other than A proto-article SHOULD NOT be propagated in that form to other than
injecting agents. injecting agents.
A proto-article has the same format as a normal article except that A proto-article has the same format as a normal article except that
some of the following mandatory headers MAY be omitted: Message-Id, some of the following mandatory header fields MAY be omitted:
Date, Path (and even From if the particular injecting agent can Message-Id, Date, Path (and even From if the particular injecting
derive that information from other sources). However, if it is agent can derive that information from other sources). However, if
intended to offer the proto-article to two or more injecting agents it is intended to offer the proto-article to two or more injecting
in parallel, then it is only the Path header that MAY be omitted. agents in parallel, then it is only the Path header field that MAY be
The headers that can be omitted MUST NOT contain invalid values; they omitted. The header fields that can be omitted MUST NOT contain
MUST either be correct or not present at all. invalid values; they MUST either be correct or not present at all.
[Maybe omit that last sentence.] [Maybe omit that last sentence.]
NOTE: An article that is offered for reinjection has, by NOTE: An article that is offered for reinjection has, by
definition, already been injected once, and is not therefore to definition, already been injected once, and is not therefore to
be considered as a proto-article. Hence a genuine proto-article be considered as a proto-article. Hence a genuine proto-article
will not contain any Injection-Date header nor any '%' <path- will not contain any Injection-Date header field nor any
delimiter> in its Path header. It MAY contain <path-identity>s "POSTED" in its Path header field, though that header field MAY
with other <path-delimiter>s in the pre-injection portion of its contain <path-identity>s corresponding to machines traversed
Path header (a-5.6.3). between the posting agent and the injecting agent proper.
[Assuming relevant mention of <path-delimiter> conventions in USEFOR.]
7.2.2. Procedure to be followed by Injecting Agents 7.2.2. Procedure to be followed by Injecting Agents
An injecting agent receives (proto-)articles from posting and An injecting agent receives (proto-)articles from posting and
followup agents. It verifies them, adds headers where required, and followup agents. It verifies them, adds header fields where required,
then either forwards them to a moderator or injects them by passing and then either forwards them to a moderator or injects them by
them to serving or relaying agents. It MUST NOT forward an already passing them to serving or relaying agents. It MUST NOT forward an
injected article to a moderator. already injected article to a moderator.
News Article Architecture and Protocols July 2005
An injecting agent processes articles as follows: An injecting agent processes articles as follows:
1. It MUST remove any Injection-Info or Complaints-To header already 1. It MUST remove any Injection-Info header field already present
present (though it might be useful to copy them to suitable X- (though it might be useful to copy it to a suitable "X-" header
headers). It SHOULD likewise remove any NNTP-Posting-Host, X- field). It SHOULD likewise remove any NNTP-Posting-Host, X-Trace,
Trace, or other non-standard tracing header. or other non-standard tracing header field.
2. It SHOULD verify that the article is from a trusted source, and 2. It SHOULD verify that the article is from a trusted source, and
MAY reject articles in which headers contain unverified email MAY reject articles in which header fields contain unverified
addresses, that is, addresses which are not known to be valid for email addresses, that is, addresses which are not known to be
the trusted source, though it would be perverse to reject valid for the trusted source, though it would be perverse to
intentionally unverifiable addresses such as those ending in reject intentionally unverifiable addresses such as those ending
".invalid" (7.5). in ".invalid" (7.5).
News Article Architecture and Protocols February 2005
3. It SHOULD reject any article whose Date header (F-3.1.2) is more 3. It SHOULD reject any article whose Date header field (F-3.1.2) is
than 24 hours into the future (and MAY use a margin less than that more than 24 hours into the future (and MAY use a margin less than
24 hours). It MUST (except when reinjecting) reject any article that 24 hours). It MUST (except when reinjecting) reject any
with an Injection-Date header already present (and SHOULD do article with an Injection-Date header field already present (and
likewise with any NNTP-Posting-Date header). When reinjecting it SHOULD do likewise with any NNTP-Posting-Date header field). When
MAY, in the absence of any Injection-Date header, reject any reinjecting it MAY, in the absence of any Injection-Date header
article whose Date header appears to be stale (e.g. more than 72 field, reject any article whose Date header field appears to be
hours into the past). stale (e.g. more than 72 hours into the past).
4. It MUST reject any article that does not have the proper mandatory 4. It MUST reject any article that does not have the proper mandatory
headers for a proto-article (except, when reinjecting, for the header fields for a proto-article (except, when reinjecting, for
Injection-Date header), or which contains any header that does not the Injection-Date header field), or which contains any header
have legal contents. It SHOULD reject any article which contains field that does not have legal contents. It SHOULD reject any
any header deprecated for Netnews (F-3). It SHOULD reject any article which contains any header field deprecated for Netnews
article whose Newsgroups header does not contain at least one (e.g. as in [RFC 2298]). It SHOULD reject any article whose
<newsgroup-name> for an existing group (as listed by its Newsgroups header field does not contain at least one <newsgroup-
associated serving agent) and it MAY reject any <newsgroup-name> name> for an existing group (as listed by its associated serving
which, although syntactically correct, violates a policy agent) and it MAY reject any <newsgroup-name> which violates one
restriction established, for some (sub-)hierarchy, by an agency of the restrictions in F-3.1.5 or which, although otherwise
with the appropriate authority (1.2). Observe that crossposting correct, violates a policy restriction established, for some
to unknown newsgroups is not precluded provided at least one of (sub-)hierarchy, by an agency with the appropriate authority
those in the Newsgroups header is listed. (1.2). Observe that crossposting to unknown newsgroups is not
[The reference to F-3 presupposes some mention of deprecated headers in precluded provided at least one of those in the Newsgroups header
there.] field is listed.
NOTE: This ability to reject <newsgroup-name>s in breach of NOTE: This ability to reject <newsgroup-name>s in breach of
established policy does not extend to relaying agents, though it established policy does not extend to relaying agents, though it
might be reasonable for posting agents to do it. might be reasonable for posting agents to do it.
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, Date and From headers (and their contents) MUST be 6. The Message-ID, Date and From header fields (with appropriate
added when not already present. A User-Agent header MAY be added contents) MUST be added when not already present. A User-Agent
(or an already present User-Agent header MAY be augmented) so as header field MAY be added (or an already present User-Agent header
to identify the software (e.g. "INN/1.7.2") used by the injecting field MAY be augmented) so as to identify the software (e.g.
agent. "INN/1.7.2") used by the injecting agent.
NOTE: The Message-ID, Date and From headers will already be News Article Architecture and Protocols July 2005
NOTE: The Message-ID, Date and From fields will already be
present during reinjection. present during reinjection.
7. The injecting agent MUST NOT alter the body of the article in any 7. The injecting agent MUST NOT alter the body of the article in any
way (including any change of Content-Transfer-Encoding). It MAY way (including any change of Content-Transfer-Encoding). It MAY
(except when reinjecting) add other headers not already provided (except when reinjecting) add other header fields not already
by the poster, but SHOULD NOT alter, delete, or reorder any provided by the poster, but SHOULD NOT alter, delete, or reorder
existing header, with the specific exception of "tracing" headers any existing header field, with the specific exception of the
such as Injection-Info and Complaints-To, which are to be removed "tracing" header field Injection-Info, which is to be removed as
as already mentioned. It MAY also, as an interim measure pending already mentioned.
widespread adoption of the newly introduced (F-3.1.5) folding
whitespace, reformat the Newsgroups and any Followup-To header by
removing any such whitespace inserted by the posting agent.
News Article Architecture and Protocols February 2005
[Again, presupposes some mention in F-3.1.5.]
8. If the Newsgroups header contains one or more moderated groups and 8. If the Newsgroups header field contains one or more moderated
the article does NOT contain an Approved header, the injecting groups and the article does NOT contain an Approved header field,
agent MUST forward it to a moderator as specified in section 7.2.3 the injecting agent MUST forward it to a moderator as specified in
below. section 7.2.3 below.
9. Otherwise, a Path header with a <tail-entry> (F-3.1.6) MUST be 9. Otherwise, a Path header field with a <tail-entry> (F-3.1.6) MUST
correctly added if not already present. During reinjection, the be correctly added if not already present. During reinjection, the
existing Path header SHOULD be retained. existing Path header field SHOULD be retained.
10.It MUST then prepend the <path-identity> of the injecting agent 10.It MUST then prepend the <path-identity> of the injecting agent,
and a '%' <path-delimiter> (which serves to separate the pre- followed by a '!', the <path-keyword> "POSTED" and a further "!"
injection and post-injection regions of the Path header) to the (or "!!" if appropriate) to the content of the Path header field;
content of the Path header; this SHOULD then be followed by CRLF this header field SHOULD then be folded if it would otherwise
and WSP if it would otherwise result in a line longer than 79 result in a header line of excessive length. The prepended
characters. The prepended <path-identity> MUST be an FQDN <path-identity> MUST be an FQDN mailable address (2.3).
mailable address (a-5.6.2). See a-5.6.4 for the significance of
the various <path-delimiter>s.
NOTE: This could result in more that one '%' <path-delimiter> in NOTE: This could result in more that one "POSTED" <path-keyword>
the case of reinjection. in the case of reinjection.
[There are unresolved issues with regard to the Path header; hence the
continued reference to [ARTICLE] above.]
11. An Injection-Info header (F-3.2.13) SHOULD be added, identifying 11.An Injection-Info header field (F-3.2.14) SHOULD be added,
the trusted source of the article, and a suitable Complaints-To identifying the trusted source of the article and possibly an
header (a-6.20) MAY be added. Each injecting agent SHOULD use a address for mailing complaints to. Each injecting agent SHOULD
consistent form of the Injection-Info header for all articles use a consistent form of the Injection-Info header field for all
emanating from the same or similar origins. articles emanating from the same or similar origins.
[There are unresolved issues concerning the Complaints-To header, so the
above step may yet be reworded in terms of a parameter of the
Injection-Info header.]
NOTE: The step above is the only place in which an Injection- NOTE: The step above is the only place in which an Injection-
Info or Complaints-To header is to be created. It follows that Info header field is to be created. It follows that this header
these headers MUST NOT be created, replaced, changed or deleted field MUST NOT be created, replaced, changed or deleted by any
by any other agent (except during reinjection, in which case other agent (except during reinjection, in which case it will
they will always relate to the latest injection and are, to that always relate to the latest injection and is, to that extent,
extent, regarded as variant headers). regarded as a variant header field).
12.The injecting agent MUST then add an Injection-Date header (F- 12.The injecting agent MUST then add an Injection-Date header field
3.1.7) if one is not already present, but it MUST NOT alter, or (F-3.2.1) if one is not already present, but it MUST NOT alter, or
delete, an already present Injection-Date header (and likewise delete, an already present Injection-Date header field (and
SHOULD NOT alter, or delete, an already present NNTP-Posting-Date likewise SHOULD NOT alter, or delete, an already present NNTP-
header). Finally, it forwards the article to one or more relaying Posting-Date header field). Finally, it forwards the article to
or serving agents, and the injection process is to be considered one or more relaying or serving agents, and the injection process
complete. is to be considered complete.
NOTE: The step above is the only place where an Injection-Date NOTE: The step above is the only place where an Injection-Date
header is to be created It follows that it MUST NOT subsequently header field is to be created It follows that it MUST NOT
be replaced, changed or deleted by any other agent, even during subsequently be replaced, changed or deleted by any other agent,
reinjection.
News Article Architecture and Protocols February 2005 News Article Architecture and Protocols July 2005
even during reinjection.
7.2.3. Procedure for Forwarding to a Moderator 7.2.3. Procedure for Forwarding to a Moderator
An injecting agent forwards ar article to a moderator as follows: An injecting agent forwards an article to a moderator as follows:
1. It MUST forward it to the moderator of the first (leftmost) 1. It MUST forward it to the moderator of the first (leftmost)
moderated group listed in the Newsgroups header, customarily via moderated group listed in the Newsgroups header field, customarily
email, (see 7.8 for how that moderator may forward it to further via email, (see 7.8 for how that moderator may forward it to
moderators). There are two possibilities for doing this: further moderators). There are two possibilities for doing this:
(a) The complete article is encapsulated (headers and all) within (a) The complete article is encapsulated (header fields and all)
the email, preferably using the Content-Type within the email, preferably using the Content-Type
"application/news-transmission" (5.1) with any usage "application/news-transmission" (5.1) 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 header fields, or of
those headers during transport through email. changes to those fields during transport through email.
(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 header fields (e.g. a To header field)
necessary for an email. The existing Message-ID header SHOULD as are necessary for an email. The existing Message-ID header
be retained. field SHOULD be retained.
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.
2. This standard does not prescribe how the email address of the 2. 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
skipping to change at page 30, line 57 skipping to change at page 32, line 5
for "news.announce.important" would be emailed to "news- for "news.announce.important" would be emailed to "news-
announce-important@forwardingagent.example". announce-important@forwardingagent.example".
7.3. Duties of a Relaying Agent 7.3. 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.
News Article Architecture and Protocols July 2005
An article SHOULD NOT be relayed unless the sending agent has been An article SHOULD NOT be relayed unless the sending agent has been
configured to supply and the receiving agent to receive at least one configured to supply and the receiving agent to receive at least one
of the <newsgroup-name>s in its Newsgroups header and at least one of of the <newsgroup-name>s in its Newsgroups header field and at least
the <dist-name>s in its Distribution header, if any. Exceptionally, one of the <dist-name>s in its Distribution header field, if any.
Exceptionally, ALL relaying agents are deemed willing to supply or
News Article Architecture and Protocols February 2005 accept the <dist-name> "world", and NO relaying agent should supply
or accept the <dist-name> "local".
ALL relaying agents are deemed willing to supply or accept the
<dist-name> "world", and NO relaying agent should supply or accept
the <dist-name> "local".
However, if the particular implementation does not relay non-existent However, if the particular implementation does not relay non-existent
newsgroups, even when included in the Newsgroups header and implied newsgroups, even when included in the Newsgroups header field and
(e.g. by some "wild card" notation) in the configuration tables, then implied (e.g. by some "wild card" notation) in the configuration
the agent MUST examine all group control messages (6.2) in order to tables, then the agent MUST examine all group control messages (6.2)
ensure that relaying of those messages proceeds normally. in order to ensure that relaying of those messages proceeds normally.
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,
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
skipping to change at page 31, line 42 skipping to change at page 32, line 46
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. A similar possibility for reading agents to filter notice. A similar possibility for reading agents to filter
distributions is also suggested in [USEAGE]) for the same distributions is also suggested in [USEAGE]) for the same
reason. reason.
In order to avoid unnecessary relaying, an article SHOULD NOT be In order to avoid unnecessary relaying, an article SHOULD NOT be
relayed if the <path-identity> of the receiving agent (or some known relayed if the <path-identity> of the receiving agent (or some known
alias thereof) appears in its Path header. alias thereof) appears as a <path-identity> (excluding within the
<tail-entry>) in its Path header field.
A relaying agent processes articles as follows: A relaying agent processes articles as follows:
1. It MUST establish the trusted identity of the source of the 1. It MUST establish the trusted identity of the source of the
article and compare it with the leftmost <path-identity> of the article and compare it with the leftmost <path-identity> of the
Path header's content. If it matches it MUST then prepend its own Path header field's content. If it matches it MUST then prepend
<path-identity> and a '/' <path-delimiter> to that content; this its own <path-identity> and a '!!' <path-delimiter> to that
SHOULD then be followed by CRLF and WSP if it would otherwise content. If it does not match then it prepends instead two entries
result in a line longer than 79 characters. If it does not match to that content; firstly the true established <path-identity> of
then it prepends instead two entries to that content; firstly the the source followed by a '!', the <path-keyword> "MISMATCH" and a
true established <path-identity> of the source followed by a '?' further '!', and then, to the left of that, its own <path-
<path-delimiter>, and then, to the left of that, its own <path- identity> followed by a '!!' <path-delimiter> as usual. This
identity> followed by a '/' <path-delimiter> as usual. This
prepending of two entries SHOULD NOT be done if the provided and prepending of two entries SHOULD NOT be done if the provided and
established identities match. See a-5.6.4 for the significance of
the various <path-delimiter>s.
News Article Architecture and Protocols February 2005 News Article Architecture and Protocols July 2005
[All subject to unresolved issues concerning the Path header.] established identities match. This header field SHOULD then be
folded if it would otherwise result in a header line of excessive
length.
[It has been suggested that relaying agents should be permitted to
prepend more than the one or two entries permitted above.]
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).
2. It MUST examine the Injection-Date header (or, if that is absent, 2. It MUST examine the Injection-Date header field (or, if that is
the Date header) and reject the article as stale (F-3.1.7) if that absent, the Date header field) and reject the article as stale
predates the earliest articles of which it normally keeps record, (F-3.2.1) if that predates the earliest articles of which it
or if it is more than 24 hours into the future (the margin MAY be normally keeps record, or if it is more than 24 hours into the
less than that 24 hours). future (the margin MAY be less than that 24 hours).
3. It SHOULD reject any article that does not include all the 3. It SHOULD reject any article that does not include all the
mandatory headers (section F-3.1). mandatory header fields (section F-3.1).
4. It MAY reject any article whose headers do not have legal 4. It MAY reject any article whose header fields do not have legal
contents. 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).
NOTE: Even though commonly derived from the domain name of the NOTE: Even though commonly derived from the domain name of the
originating site (and domain names are case-insensitive), a originating site (and domain names are case-insensitive), a
message identifier MUST NOT be altered in any way during message identifier MUST NOT be altered in any way during
transport, or when copied (as into a References header), and transport, or when copied (as when forming a References header
thus a simple (case-sensitive) comparison of octets will always field), and thus a simple (case-sensitive) comparison of octets
suffice to recognize that same message identifier wherever it will always suffice to recognize that same message identifier
subsequently reappears. wherever it subsequently reappears.
NOTE: These requirements are to be contrasted with those of the NOTE: These requirements are to be contrasted with those of the
un-normalized msg-ids defined by [RFC 2822], which may perfectly un-normalized msg-ids defined by [RFC 2822], which may perfectly
legitimately become normalized (or vice versa) during transport legitimately become normalized (or vice versa) during transport
or copying in email systems. or copying in email systems.
NOTE: Some old software may treat message identifiers that
differ only in case within their <id-right> part as equivalent,
and implementors of agents that generate message identifiers
should be aware of this.
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 field) issued
poster or by some other trusted entity. by its poster or by some other trusted entity.
7. It MAY reject any article without an Approved header posted to 7. It MAY reject any article without an Approved header field posted
newsgroups known to be moderated (this practice is strongly to newsgroups known to be moderated (this practice is strongly
recommended, but the information necessary to do so may not be recommended, but the information necessary to do so may not be
available to all agents). available to all agents).
8. It MAY delete any Xref header that is present. 8. It MAY delete any Xref header field that is present.
News Article Architecture and Protocols February 2005
9. Finally, it passes the articles on to neighbouring relaying and 9. Finally, it passes the articles on to neighbouring relaying and
serving agents. serving agents.
News Article Architecture and Protocols July 2005
If the article is rejected as being invalid, unwanted or unacceptable If the article is rejected as being invalid, unwanted or unacceptable
due to site policy, the agent that passed the article to the relaying due to site policy, the agent that passed the article to the relaying
agent SHOULD be informed (such as via an NNTP 43x response code) that agent SHOULD be informed (such as via an NNTP 43x response code) that
relaying failed. In order to prevent a large number of error messages relaying failed. In order to prevent a large number of error messages
being sent to one location, relaying agents MUST NOT inform any other being sent to one location, relaying agents MUST NOT inform any other
external entity that an article was not relayed UNLESS that external external entity that an article was not relayed UNLESS that external
entity has explicitly requested that it be informed of such errors. entity has explicitly requested that it be informed of such errors.
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 except for headers designated as variant (2.3). In article except for header fields designated as variant (2.4). In
particular particular
o they MUST NOT create or augment a User-Agent header in order to o they MUST NOT create or augment a User-Agent header field in
identify themselves; order to identify themselves;
o they MUST NOT rewrite the Newsgroups header in any way, even if o they MUST NOT rewrite the Newsgroups header field in any way,
some supposedly non-existent newsgroup is included; even if some supposedly non-existent newsgroup is included;
o they MUST NOT refold any header (i.e. they must pass on the o they MUST NOT refold any header field (i.e. they must pass on the
folding as received), even to remove FWS from a Newsgroups folding as received);
header; o they MUST NOT alter the Date header field or the Injection-Date
o they MUST NOT alter the Date header or the Injection-Date header; header field;
o they MUST NOT delete any unrecognized header whose header-name is o they MUST NOT delete any unrecognized header field whose field
syntactically correct (whether or not it is registered with IANA name is syntactically correct (whether or not it is registered
[RFC 3864]); with IANA [RFC 3864]);
o they MUST NOT change the Content-Transfer-Encoding of the body or o they MUST NOT change the Content-Transfer-Encoding of the body or
any body part. any body part;
o they MUST transmit lines of arbitrary length and articles of
arbitrary size.
7.3.1. Path-Header Example 7.3.1. Path Header Field Example
Path: foo.isp.example/ Path: foo.isp.example!!foo-server!!bar.isp.example!MISMATCH!
foo-server/bar.isp.example?10.123.12.2/old.site.example! 2001:DB8:0:0:8:800:200C:417A!!old.site.example!barbaz!!
barbaz/baz.isp.example%dialup123.baz.isp.example!not-for-mail baz.isp.example!POSTED!!dialup123.baz.isp.example!not-for-mail
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, as indicated by the <path-keyword> "POSTED"
abuse@baz.isp.example). The injector has taken care to record (complaints may be addressed to abuse@baz.isp.example). The
that it got it from dialup123.baz.isp.example. "not-for-mail" is injector has chosen to record that it got it from
a dummy <tail-entry>, though sometimes a real userid is put dialup123.baz.isp.example. "not-for-mail" is a dummy <tail-
there. 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 old.site.example, as "barbaz". at least to old.site.example, as "barbaz".
Barbaz relayed it to old.site.example, which does not yet Barbaz relayed it to old.site.example, which does not yet
conform to this standard (hence the '!' <path-delimiter). So one conform to this standard (hence the '!' <path-delimiter). So one
cannot be sure that it really came from barbaz. cannot be sure that it really came from barbaz.
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 IPv6
address [10.123.12.2], and claiming (by using the '/' <path- address [2001:DB8:0:0:8:800:200C:417A], and claiming (by using
delimiter>) to have verified that it came from old.site.example. the '!!' <path-delimiter>) to have verified that it came from
old.site.example.
News Article Architecture and Protocols February 2005 News Article Architecture and Protocols July 2005
[10.123.12.2] relayed it to "foo-server" which, not being [2001:DB8:0:0:8:800:200C:417A] relayed it to "foo-server" which,
convinced that it truly came from [10.123.12.2], did a reverse not being convinced that it truly came from
lookup on the actual source and concluded it was known as [2001:DB8:0:0:8:800:200C:417A], inserted the <path-keyword>
bar.isp.example (that is not to say that [10.123.12.2] was not a "MISMATCH" and then did a reverse lookup on the actual source
correct IP address for bar.isp.example, but simply that that and concluded it was known as bar.isp.example (that is not to
connection could not be substantiated by foo-server). Observe say that [2001:DB8:0:0:8:800:200C:417A] was not a correct IPv6
that foo-server has now added two entries to the Path. address for bar.isp.example, but simply that that connection
could not be substantiated by foo-server). Observe 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-server and barbaz decided to fold the line,
fold the line, on the grounds that it seemed to be getting a on the grounds that it seemed to be getting a little too long.
little too long.
7.4. Duties of a Serving Agent 7.4. 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-locator> (usually in the form of a decimal number - see F- <article-locator> (usually in the form of a decimal number - see F-
3.2.10). 3.2.11).
A serving agent MUST maintain a list of the newsgroups it stores in A serving agent MUST maintain a list of the newsgroups it stores in
its news database showing the moderation status of each one (see its news database showing the moderation status of each one (see
6.2.1), and SHOULD include in that list all groups likely to be 6.2.1), and SHOULD include in that list all groups likely to be
crossposted to from those groups (e.g. all other groups in the same crossposted to from those groups (e.g. all other groups in the same
hierarchy(ies)). hierarchy(ies)).
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
common for serving agents to make them available in a pseudo- common for serving agents to make them available in a pseudo-
newsgroup named "control" or in a pseudo-newsgroup in a sub- newsgroup named "control" or in a pseudo-newsgroup in a sub-
hierarchy under "control." (e.g. "control.cancel"). hierarchy under "control." (e.g. "control.cancel").
A serving agent MAY decline to accept an article if the Path header A serving agent MAY decline to accept an article if the Path header
contains some <path-identity> whose articles the serving agent does field contains some <path-identity> whose articles the serving agent
not want, as a matter of local policy. does not want, as a matter of local policy.
NOTE: This last facility is sometimes used to detect and decline NOTE: This last facility is sometimes used to detect and decline
control messages (notably cancel messages) which have been control messages (notably cancel messages) which have been
deliberately seeded with a <path-identity> to be "aliased out" deliberately seeded with a <path-identity> to be "aliased out"
by sites not wishing to act upon them. by sites not wishing to act upon them.
[INN at least does this. It might be argued that it is not necessary to [INN at least does this. It might be argued that it is not necessary to
mention it here.] mention it here.]
A serving agent processes articles as follows: A serving agent processes articles as follows:
News Article Architecture and Protocols February 2005 News Article Architecture and Protocols July 2005
1. It MUST establish the trusted identity of the source of the 1. It MUST establish the trusted identity of the source of the
article and modify the Path header as for a relaying agent (7.3). article and modify the Path header field as for a relaying agent
(7.3).
2. It MUST examine the Injection-Date header (or, if that is absent, 2. It MUST examine the Injection-Date header field (or, if that is
the Date header) and reject the article as stale (F-3.1.7) if that absent, the Date header field) and reject the article as stale
predates the earliest articles of which it normally keeps record, (F-3.2.1) if that predates the earliest articles of which it
or if it is more than 24 hours into the future (the margin MAY be normally keeps record, or if it is more than 24 hours into the
less than that 24 hours). future (the margin MAY be less than that 24 hours).
3. It MUST reject any article that does not include all the mandatory 3. It MUST reject any article that does not include all the mandatory
headers (section F-3.1), or which contains any header that does header fields (section F-3.1), or which contains any header field
not have legal contents. 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 articles is usually kept database of message identifiers of recent articles 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 field) issued
poster or by some other trusted entity. by its poster or by some other trusted entity.
6. It MUST reject any article without an Approved header posted to 6. It MUST reject any article without an Approved header field posted
any newsgroup listed as moderated. to any newsgroup listed as moderated.
7. It MUST remove any Xref header (F-3.2.10) from each article. It 7. It MUST (exept when specially configured to preserve the
then MAY (and usually will) generate a fresh Xref header. <article-locator>s set by the sending site) remove any Xref header
field (F-3.2.11) from each article. It then MAY (and usually
will) generate a fresh Xref header field.
8. Finally, it stores the article in its news database. 8. Finally, it stores the article in its news database.
Serving agents MUST NOT create new newsgroups simply because an Serving agents MUST NOT create new newsgroups simply because an
unrecognized <newsgroup-name> occurs in a Newsgroups header (see unrecognized <newsgroup-name> occurs in a Newsgroups header field
6.2.1 for the correct method of newsgroup creation). (see 6.2.1 for the correct method of newsgroup creation).
Serving agents MUST NOT alter, delete or rearrange any part of an Serving agents MUST NOT alter, delete or rearrange any part of an
article in any other way. The list of particular cases given for article in any other way. The list of particular cases given for
relaying agents (7.3) applies here also. relaying agents (7.3) applies here also.
7.5. Duties of a Posting Agent 7.5. 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 according to [USEFOR] and other applicable policies. In valid according to [USEFOR] and other applicable policies. In
particular, they MUST NOT create any Injection-Date, Injection-Info particular, they MUST NOT create any Injection-Date or Injection-Info
or Complaints-To header. header field.
Contrary to [RFC 2822], which implies that the mailbox(es) in the Contrary to [RFC 2822], which implies that the mailbox(es) in the
From header should be that of the poster(s), a poster who does not, From header field should be that of the poster(s), a poster who does
for whatever reason, wish to use his own mailbox MAY use any mailbox not, for whatever reason, wish to use his own mailbox MAY use any
ending in the top level domain ".invalid" [RFC 2606]. mailbox ending in the top level domain ".invalid" [RFC 2606].
News Article Architecture and Protocols February 2005 News Article Architecture and Protocols July 2005
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 or sender. article of which the poster is not the author or sender.
7.6. Duties of a Followup Agent 7.6. 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. Followup agents MUST bound by all the posting agent's requirements. Followup agents MUST
create valid followups and are subject to special requirements create valid followups and are subject to special requirements
involving the Newsgroups, Subject, Distribution and References involving the Newsgroups, Subject, Distribution and References header
headers. Wherever in the following it is stated that, "by default", fields. Wherever in the following it is stated that, "by default", a
a header is to be "inherited" from one of those headers in the header field is to be "inherited" from one of those header fields in
precursor, it means that its initial content is to be copied from the the precursor, it means that its initial (semantic) content is to be
content of that precursor header. However, posters MAY then override a copy of the content of that precursor header field. However,
that default before posting if they so wish. posters MAY then override that default before posting if they so
wish.
NOTE: The Keywords header is not inheritable, though some older
newsreaders treated it as such.
NOTE: There is no provision in this standard for a followup to
have more than one precursor (though it might be permitted in
some future extension).
1. The Newsgroups header (F-3.1.5) SHOULD by default be inherited NOTE: The Keywords header field is not inheritable, though some
from the precursor's Followup-To header if present, and otherwise older newsreaders treated it as such.
from the precursor's Newsgroups header. However, if the content of
that Followup-To header consists of "poster" (and the user does
not override it), then the followup MUST NOT be posted but,
rather, is to be emailed to the precursor's poster.
2. The Subject header SHOULD by default be inherited from that of the 1. The Newsgroups header field (F-3.1.5) SHOULD by default be
precursor. The case sensitive string "Re: " MAY be prepended to inherited from the precursor's Followup-To header field if
its Subject-Content unless it already begins with that string. present, and otherwise from the precursor's Newsgroups header
field. However, if the content of that Followup-To header field
consists of "poster" (and the user does not override it), then the
followup MUST NOT be posted but, rather, is to be emailed to the
precursor's poster.
3. The Distribution header (F-3.2.6) SHOULD by default be inherited 2. The Subject header field SHOULD by default be inherited from that
from the precursor's Distribution header, if any. of the precursor. The case sensitive string "Re: " MAY be
prepended to the content of its Subject header field, unless it
already begins with that string.
4. If the precursor did not have a References header (F-3.2.1), the 3. The Distribution header field (F-3.2.7) SHOULD by default be
content of the followup's References header MUST be inherited from inherited from the precursor's Distribution header field, if any.
that of the Message-ID header of the precursor. A followup to an
article which already had a References header MUST have a
References header comprising the precursor's References header
(subject to trimming as described below) followed by CFWS and the
Message-ID header content of the precursor.
If the resulting References header is excessively long, it MAY be 4. The followup MUST (in accordance with the definition of that term)
trimmed, but the first and the last two message identifiers MUST have a References header field referring to its precursor,
NOT be removed. constructed in accordance with section 7.6.1 below.
5. If the precursor contains a Mail-Copies-To header (a-6.8), the NOTE: That "MUST" is to be contrasted with the weaker
actions to be taken, in accordance with the content of the header, recomendation using "SHOULD" applied, in [RFC 2822], to the
(and subject to manual override by the poster) are as follows: generation of "replies" in email. Moreover, in Netnews, there is
no expectation of any In-Reply-To header field in a followup.
News Article Architecture and Protocols February 2005 7.6.1. Construction of the References header field
"nobody" (or when the header is absent) The following procedure is to be used whenever some previous article
The followup agent SHOULD NOT email a copy of a posted (the "parent") is to be referred to in the References header field
followup to the poster of the precursor. (F-3.2.2) of a new article, whether in the course of generating a
followup or for some other reason (e.g. the later parts of a
multipart posting such as a FAQ, or the later parts of a
message/partial as suggested in [RFC 2046]).
"poster" News Article Architecture and Protocols July 2005
The followup agent SHOULD (if it has the necessary
capability) email a copy of a posted followup, which MUST
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.
a <copy-addr> The (semantic) content of the new article's References header field
The followup agent SHOULD likewise email a copy of a posted consists of the content of the Message-ID header field of the parent
followup, which SHOULD then be sent to the <copy-addr>. preceded, if the parent had a References header field, by the content
[There are still unresolved issues concerning the Mail-Copies-To header, of that References header field and a SP (subject to trimming as
hence the continuing reference to [ARTICLE].] described below).
When emailing a copy, the followup agent SHOULD also include a If the resulting References header field would, after unfolding,
"Posted-And-Mailed: yes" header (a-6.9). exceed 998 characters in length (including its field name but not the
[There are still unresolved issues concerning the Posted-And-Mailed final CRLF), it MUST be trimmed (and otherwise it MAY be trimmed).
header, hence the continuing reference to [ARTICLE].] Trimming involves removing any number of message identifiers from its
content, except that the first message identifier and the last two
MUST NOT be removed.
Followup agents SHOULD NOT attempt to send email to any address NOTE: There is no provision in this standard for an article to
ending in ".invalid". have more than one parent. The essential property of the
References header field, guaranteed by the procedure above and
to be preserved in any future extension, is that no article can
ever precede one of its own parents.
7.7. Duties of a Reading Agent 7.7. Duties of a Reading Agent
A reading agent downloads articles from a serving agent, as directed A reading agent downloads articles from a serving agent, as directed
by the reader, and displays them to the reader (or processes them in by the reader, and displays them to the reader (or processes them in
some other manner). It SHOULD also have the capability to show the some other manner). It SHOULD also have the capability to show the
raw article exactly as received. raw article exactly as received.
It MAY present lists of articles available for display, and MAY It MAY present lists of articles available for display, and MAY
structure those lists so as to show the relationships between the structure those lists so as to show the relationships between the
articles, as determined by the References, Subject, Date and other articles, as determined by the References, Subject, Date and other
headers (see [USEAGE] for some usual methods of doing this). header fields (see [USEAGE] for some usual methods of doing this).
[This whole section may yet get omitted] [This whole section may yet get omitted]
7.8. Duties of a Moderator 7.8. Duties of a Moderator
A Moderator receives news articles, customarily by email, decides A Moderator receives news articles, customarily by email, decides
whether to approve them and, if so, either injects them into the news whether to approve them and, if so, either injects them into the news
stream or forwards them to further moderators. stream or 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
encapsulated but without an explicit Content-Type header), or else encapsulated but without an explicit Content-Type header field), or
directly as an email already containing all the headers appropriate else directly as an email already containing all the header fields
for a Netnews article (see 7.2.2). Moderators SHOULD be prepared to appropriate for a Netnews article (see 7.2.2). Moderators SHOULD be
accept articles in either format. prepared to accept articles in either format.
A moderator processes an article, as submitted to any newsgroup that A moderator processes an article, as submitted to any newsgroup that
he moderates, as follows: he moderates, as follows:
News Article Architecture and Protocols February 2005
1. He decides, on the basis of whatever moderation policy applies to 1. He decides, on the basis of whatever moderation policy applies to
his group, whether to approve or reject the article. He MAY do his group, whether to approve or reject the article. He MAY do
this manually, or else partially or wholly with the aid of this manually, or else partially or wholly with the aid of
appropriate software for whose operation he is then responsible. appropriate software for whose operation he is then responsible.
If the article is a cancel nessage (6.3) issued by the poster of If the article is a cancel nessage (6.3) issued by the poster of
an earlier article, then he is expected to cancel that earlier an earlier article, then he is expected to cancel that earlier
News Article Architecture and Protocols July 2005
article (in which case there is no more to be done). He MAY article (in which case there is no more to be done). He MAY
modify the article if that is in accordance with the applicable modify the article if that is in accordance with the applicable
moderation policy (and in particular he MAY remove redundant moderation policy (and in particular he MAY remove redundant
headers and add Comments and other informational headers). He header fields and add Comments and other informational header
also needs to be aware if any change he makes to the article will fields). He also needs to be aware if any change he makes to the
invalidate some authentication check provided by the poster or by article will invalidate some authentication check provided by the
an earlier moderator. poster or by an earlier moderator.
If the article is rejected, then it normally fails for all the If the article is rejected, then it normally fails for all the
newsgroups for which it was intended. If it is approved, the newsgroups for which it was intended. If it is approved, the
moderator proceeds with the following steps. moderator proceeds with the following steps.
2. If the Newsgroups header contains further moderated newsgroups for 2. If the Newsgroups header field contains further moderated
which approval has not already been given, he adds an indication newsgroups for which approval has not already been given, he adds
(identifying both himself and the name of the group) that he an indication (identifying both himself and the name of the group)
approves the article, and then forwards it to the moderator of the that he approves the article, and then forwards it to the
leftmost unapproved group (which, if this standard has been moderator of the leftmost unapproved group (which, if this
followed correctly, will generally be the next moderated group to standard has been followed correctly, will generally be the next
the right of his own). There are two ways to do this: moderated group to the right of his own). There are two ways to do
this:
(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 7.2.2 for the proper method of doing this), or (see section 7.2.2 for the proper method of doing this), or
(b) he rotates the <newsgroup-name>s in the Newsgroups header to (b) he rotates the <newsgroup-name>s in the Newsgroups header
the left so that the targeted group is the leftmost moderated field to the left so that the targeted group is the leftmost
group in that header, and injects it again (thus causing the moderated group in that field, and injects it again (thus
injecting agent to forward it to the correct moderator). causing the injecting agent to forward it to the correct
However, he MUST first ensure that the article contains no moderator). However, he MUST first ensure that the article
Approved header. contains no Approved header field.
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 field
similar but differently named header if method (b) is being (or a similar but differently named header field if method (b)
used) listing all the approvals made so far, or adding a is being used) listing all the approvals made so far, or adding
separate header for each individual approval (the header X-Auth a separate header field for each individual approval (the header
is sometimes used for this purpose). The approval may also be field X-Auth is sometimes used for this purpose). The approval
confirmed with some form of digital signature (6.1). may also be confirmed with some form of digital signature (6.1).
3. If the Newsgroups header contains no further unapproved moderated 3. If the Newsgroups header field contains no further unapproved
groups, he adds an Approved header (F-3.2.8) identifying himself moderated groups, he adds an Approved header field (F-3.2.9)
and, insofar as is possible, all the other moderators who have identifying himself and, insofar as is possible, all the other
approved the article. He thus assumes responsibility for having moderators who have approved the article. He thus assumes
ensured that the article was approved by the moderators of all the responsibility for having ensured that the article was approved by
moderated groups involved. the moderators of all the moderated groups involved.
News Article Architecture and Protocols February 2005 4. The Date header field SHOULD be retained. Any Injection-Date
header field already present (though there should be none) MUST be
removed. Exceptionally, if it is known that the injecting agent
does not yet support the Injection-Date header field and the Date
header field appears to be stale (F-3.2.1) for reasons understood
by the moderator (e.g. delays in the moderation process) he MAY
substitute the current date. The Message-ID header field SHOULD
4. The Date header SHOULD be retained. Any Injection-Date header News Article Architecture and Protocols July 2005
already present (though there should be none) MUST be removed.
Exceptionally, if it is known that the injecting agent does not also be retained unless it is obviously non-compliant with this
yet support the Injection-Date header and the Date header appears standard.
to be stale (F-3.1.7) for reasons understood by the moderator
(e.g. delays in the moderation process) he MAY substitute the
current date. The Message-ID header SHOULD also be retained unless
it is obviously non-compliant with this standard.
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).
5. Any variant headers (2.3) MUST be removed, except that a Path 5. Any variant header fields (2.4) MUST be removed, except that a
header MAY be truncated to only its pre-injection region (a- Path header field MAY be truncated to only those entries following
5.6.3). Any Injection-Info header (F-3.2.13) or Complaints-To its "POSTED" <path-keyword>. Any Injection-Info header field (F-
header (a-6.20) SHOULD be removed (and if they are not, the 3.2.14) SHOULD be removed (and if not, the injecting agent will do
injecting agent will do so, as required in 7.2.2). so, as required in 7.2.2).
6. He then causes the article to be injected, having first observed 6. He then causes the article to be injected, having first observed
all the duties of a posting agent. 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.
skipping to change at page 39, line 51 skipping to change at page 40, line 45
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
transforms a news article into a different type of message, and the transforms a news article into a different type of message, and the
Incoming Gateway that transforms a message from another medium into a Incoming Gateway that transforms a message from another medium into a
news article and injects it into a news system. These are handled news article and injects it into a news system. These are handled
separately below. separately below.
The primary dictat for a gateway is: The primary diktat for a gateway is:
Above all, prevent loops. Above all, prevent loops.
Transformation of an article into another medium stands a very high Transformation of an article into another medium stands a very high
chance of discarding or interfering with the protection inherent in chance of discarding or interfering with the protection inherent in
the news system against duplicate articles. The most common problem the news system against duplicate articles. The most common problem
caused by gateways is "spews", gateway loops that cause previously caused by gateways is "spews", gateway loops that cause previously
posted articles to be reinjected repeatedly into Usenet. To prevent posted articles to be reinjected repeatedly into Usenet. To prevent
this, a gateway MUST take precautions against loops, as detailed this, a gateway MUST take precautions against loops, as detailed
News Article Architecture and Protocols February 2005
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
unintended reinjection of gated articles. Circular gatewaying unintended reinjection of gated articles. Circular gatewaying
News Article Architecture and Protocols July 2005
(gatewaying a message into another medium and then back into Netnews) (gatewaying a message into another medium and then back into Netnews)
SHOULD NOT be done; encapsulation of the article SHOULD be used SHOULD NOT be done; encapsulation of the article SHOULD be used
instead where this is necessary. instead where this is necessary.
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.
skipping to change at page 41, line 5 skipping to change at page 41, line 54
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.
News Article Architecture and Protocols February 2005
2. The Date and Injection-Date of the news article should also be 2. The Date and Injection-Date of the news article should also be
preserved if possible, for similar reasons. preserved if possible, 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
News Article Architecture and Protocols July 2005
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.
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.
5. Changes MAY be made to the Content-Transfer-Encoding of some or 5. Changes MAY be made to the Content-Transfer-Encoding of some or
all parts of the body, and even to the charsets specified in all parts of the body, and even to the charsets specified in
<encoded-word>s or in Content-Type headers, but such changes <encoded-word>s or in Content-Type header fields, but such changes
SHOULD NOT be made unless absolutely necessary. SHOULD NOT be made unless absolutely necessary.
7.9.2. Duties of an Incoming Gateway 7.9.2. 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
be possible to ensure this in the face of mangling or modification of be possible to ensure this in the face of mangling or modification of
the message, but at the very least a gateway, when given a copy of a the message, but at the very least a gateway, when given a copy of a
message it has already gated identical except for trace headers (like message it has already gated identical except for trace header fields
Received in Email or Path in Netnews) MUST NOT gate the message (like Received in Email or Path in Netnews) MUST NOT gate the message
again. An incoming gateway SHOULD take precautions against having again. An incoming gateway SHOULD take precautions against having
this rule bypassed by modifications of the message that can be this rule bypassed by modifications of the message that can be
anticipated. anticipated.
News articles prepared by gateways MUST be legal news articles. In News articles prepared by gateways MUST be legal news articles. In
particular, they MUST include all of the mandatory headers, MUST particular, they MUST include all of the mandatory header fields,
fully conform to the restrictions on said headers, and SHOULD exclude MUST fully conform to the restrictions on those fields, and SHOULD
any deprecated headers (F-3). This often requires that a gateway exclude any deprecated header fields (e.g. as in [RFC 2298]). This
function not only as a relaying agent, but also partly as a posting often requires that a gateway function not only as a relaying agent,
agent, aiding in the synthesis of a conforming article from non- but also partly as a posting agent, aiding in the synthesis of a
conforming input. conforming article from non-conforming input.
[Presupposes suitable mention of deprecated headers in USEFOR.]
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 field) without removing or renaming
header. Gateways MAY, however, generate their own cancel messages, that header field. Gateways MAY, however, generate their own cancel
under the general allowance for injecting agents to cancel their own messages, under the general allowance for injecting agents to cancel
messages ([USEAGE]). If a gateway receives a message that it can their own messages ([USEAGE]). If a gateway receives a message that
determine is a valid equivalent of a cancel message in the medium it it can determine is a valid equivalent of a cancel message in the
is gatewaying, it SHOULD discard that message without gatewaying it, medium it is gatewaying, it SHOULD discard that message without
generate a corresponding cancel message of its own, and inject that gatewaying it, generate a corresponding cancel message of its own,
cancel message. and inject that cancel message.
News Article Architecture and Protocols February 2005
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
News Article Architecture and Protocols July 2005
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.
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 field in news, it SHOULD be used in the
the message identifier of the news article, perhaps with formation of 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 F-3.1.3. Such transformations SHOULD be designed so syntax in section F-3.1.3. 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 field.
NOTE: Message identifiers play a central role in the prevention NOTE: Message identifiers play a central role in the prevention
of duplicates, and their correct use by gateways will do much to of duplicates, and their correct use by gateways will do much to
prevent loops. Netnews does, however, require that message prevent loops. Netnews does, however, require that message
identifiers be unique, and therefore message identifiers from identifiers be unique, and therefore message identifiers from
other media may not be suitable for use without modification. A other media may not be suitable for use without modification. A
balance must be struck by the gateway between preserving balance must be struck by the gateway between preserving
information used to prevent loops and generating unique message information used to prevent loops and generating unique message
identifiers. identifiers.
skipping to change at page 42, line 57 skipping to change at page 43, line 50
list into the world-wide Usenet newsgroups, both of which list into the world-wide Usenet newsgroups, both of which
preserve the email message identifier. Each newsgroup may then preserve the email message identifier. Each newsgroup may then
receive a portion of the messages (different sites seeing receive a portion of the messages (different sites seeing
different portions). In these cases, where there is no one different portions). In these cases, where there is no one
"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 no injection-date header field with the gateway's current date. If no injection-date
information is available, the gateway MUST supply an Injection-Date information is available, the gateway MUST supply an Injection-Date
header with whatever date information is available, and otherwise header field with whatever date information is available, and
with the gateway's current date. If only partial information is otherwise with the gateway's current date. If only partial
information is available (e.g. date but not time), this SHOULD be
News Article Architecture and Protocols February 2005 fleshed out to a full Date and/or Injection-Date header field by
adding default values rather than discarding this information. Only
in very exceptional circumstances should Date information be
discarded, as it plays an important role in preventing reinjection of
old messages.
available (e.g. date but not time), this SHOULD be fleshed out to a News Article Architecture and Protocols July 2005
full Date and/or Injection-Date header by adding default values
rather than discarding this information. Only in very exceptional
circumstances should Date information be discarded, as it plays an
important role in preventing 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 field to the news
forms containing the <mailbox> of the administrator of the gateway. article it forms containing the <mailbox> of the administrator of the
Problems with the gateway may be reported to this <mailbox>. The gateway. Problems with the gateway may be reported to this
<display-name> portion of this <mailbox> SHOULD indicate that the <mailbox>. The <display-name> portion of this <mailbox> SHOULD
entity responsible for injection of the message is a gateway. If the indicate that the entity responsible for injection of the message is
original message already had a Sender header, it SHOULD be renamed so a gateway. If the original message already had a Sender header field,
that its contents can be preserved. it SHOULD be renamed so that its contents can be preserved.
7.9.3. Example 7.9.3. Example
To illustrate the type of precautions that should be taken against To illustrate the type of precautions that should be taken against
loops, here is an example of the measures taken by one particular loops, here is an example of the measures taken by one particular
combination of mail-to-news and news-to-mail gateways at Stanford combination of mail-to-news and news-to-mail gateways at Stanford
University designed to handle bidirectional gatewaying between University designed to handle bidirectional gatewaying between
mailing lists and unmoderated groups. mailing lists and unmoderated groups.
1. The news-to-mail gateway preserves the message identifier of the 1. The news-to-mail gateway preserves the message identifier of the
news article in the generated email message. The mail-to-news news article in the generated email message. The mail-to-news
gateway likewise preserves the email message identifier provided gateway likewise preserves the email message identifier provided
that it is syntactically valid for Netnews. This allows the news that it is syntactically valid for Netnews. This allows the news
system's built-in suppression of duplicates to serve as the first system's built-in suppression of duplicates to serve as the first
line of defense against loops. line of defense against loops.
2. The news-to-mail gateway adds an X-Gateway header to all messages 2. The news-to-mail gateway adds an X-Gateway header field to all
it generates. The mail-to-news gateway discards any incoming messages it generates. The mail-to-news gateway discards any
messages containing this header. This is robust against mailing incoming messages containing this header field. This is robust
list managers that replace the message identifier, and against any against mailing list managers that replace the message identifier,
number of email hops, provided that the other message headers are and against any number of email hops, provided that the other
preserved. message header fields are preserved.
3. The mail-to-news gateway inserts the host name from which it 3. The mail-to-news gateway prepends the host name from which it
received the email message in the pre-injection region of the Path received the email message to the content of the Path header
(a-5.6.3). The news-to-mail gateway refuses to gateway any field. The news-to-mail gateway refuses to gateway any message
message that contains the list server name in the pre-injection that contains the list server name in its Path header field. This
region of its Path header. This is robust against any amount of is robust against any amount of munging of the message header
munging of the message headers by the mailing list, provided that fields by the mailing list, provided that the email only goes
the email only goes through one hop. through one hop.
4. The mail-to-news gateway is designed never to generate bounces to 4. The mail-to-news gateway is designed never to generate bounces to
the envelope sender. Instead, articles that are rejected by the the envelope sender. Instead, articles that are rejected by the
news server (for reasons not warranting silent discarding of the news server (for reasons not warranting silent discarding of the
message) result in a bounce message sent to an errors address message) result in a bounce message sent to an errors address
known not to forward to any mailing lists, so that they can be known not to forward to any mailing lists, so that they can be
handled by the news administrators. handled by the news administrators.
These precautions have proven effective in practice at preventing These precautions have proven effective in practice at preventing
loops for this particular application (bidirectional gatewaying loops for this particular application (bidirectional gatewaying
between mailing lists and locally distributed newsgroups where both between mailing lists and locally distributed newsgroups where both
News Article Architecture and Protocols February 2005
gateways can be designed together). General gatewaying to world-wide gateways can be designed together). General gatewaying to world-wide
newsgroups poses additional difficulties; one must be very wary of newsgroups poses additional difficulties; one must be very wary of
strange configurations, such as a newsgroup gated to a mailing list strange configurations, such as a newsgroup gated to a mailing list
which is in turn gated to a different newsgroup. which is in turn gated to a different newsgroup.
News Article Architecture and Protocols July 2005
8. Security and Related Considerations 8. Security and Related Considerations
There is no security. Don't fool yourself. Usenet is a prime example There is no security. Don't fool yourself. Usenet is a prime example
of an Internet Adhocratic-Anarchy; that is, an environment in which of an Internet Adhocratic-Anarchy; that is, an environment in which
trust forms the basis of all agreements. It works. trust forms the basis of all agreements. It works.
8.1. Leakage 8.1. Leakage
Articles which are intended to have restricted distribution are Articles which are intended to have restricted distribution are
dependent on the goodwill of every site receiving them. The dependent on the goodwill of every site receiving them. The
"Archive: no" header (F-3.2.11) is available as a signal to automated "Archive: no" header field (F-3.2.12) is available as a signal to
archivers not to file an article, but that cannot be guaranteed. automated archivers not to file an article, but that cannot be
guaranteed.
The Distribution header makes provision for articles which should not The Distribution header field makes provision for articles which
be propagated beyond a cooperating subnet. The key security word here should not be propagated beyond a cooperating subnet. The key
is "cooperating". When a machine is not configured properly, it may security word here is "cooperating". When a machine is not configured
become uncooperative and tend to distribute all articles. properly, it may become uncooperative and tend to distribute all
articles.
The flooding algorithm is extremely good at finding any path by which The flooding algorithm is extremely good at finding any path by which
articles can leave a subnet with supposedly restrictive boundaries, articles can leave a subnet with supposedly restrictive boundaries,
and substantial administrative effort is required to avoid this. and substantial administrative effort is required to avoid this.
Organizations wishing to control such leakage are strongly advised to Organizations wishing to control such leakage are strongly advised to
designate a small number of official gateways to handle all news designate a small number of official gateways to handle all news
exchange with the outside world (however, making such gateways too exchange with the outside world (however, making such gateways too
restrictive can also encourage the setting up of unofficial paths restrictive can also encourage the setting up of unofficial paths
which can be exceedingly hard to track down). which can be exceedingly hard to track down).
skipping to change at page 45, line 5 skipping to change at page 45, line 57
to their precursors, or which quote their precursors in full with the to their precursors, or which quote their precursors in full with the
addition of minimal extra material (especially if this process is addition of minimal extra material (especially if this process is
iterated), and by crossposting to, or setting followups to, totally iterated), and by crossposting to, or setting followups to, totally
unrelated newsgroups. unrelated newsgroups.
Many have argued that "spam", massively multiposted (and to a lesser Many have argued that "spam", massively multiposted (and to a lesser
extent massively crossposted) articles, usually for advertising extent massively crossposted) articles, usually for advertising
purposes, also constitutes a DoS attack in its own regard. This may purposes, also constitutes a DoS attack in its own regard. This may
be so. be so.
News Article Architecture and Protocols February 2005
Such articles intended to deny service, or other articles of an Such articles intended to deny service, or other articles of an
inflammatory nature, may also have their From or Reply-To addresses inflammatory nature, may also have their From or Reply-To addresses
set to valid but incorrect email addresses, thus causing large set to valid but incorrect email addresses, thus causing large
volumes of email to descend on the true owners of those addresses. volumes of email to descend on the true owners of those addresses.
Similar effects could be caused by any email header which could cause News Article Architecture and Protocols July 2005
every reading agent receiving it to take some externally visible
action. For example, the Disposition-Notification-To header defined Similar effects could be caused by any email header field which could
in [RFC 2298] could cause huge numbers of acknowledgements to be cause every reading agent receiving it to take some externally
emailed to an unsuspecting third party (for which reason [RFC 2298] visible action. For example, the Disposition-Notification-To header
declares that that header SHOULD NOT be used in Netnews). field defined in [RFC 2298] could cause huge numbers of
acknowledgements to be emailed to an unsuspecting third party (for
which reason [RFC 2298] declares that that header field SHOULD NOT be
used in Netnews).
It is a violation of this standard for a poster to use as his address It is a violation of this standard for a poster to use as his address
a <mailbox> which he is not entitled to use. Even addresses with an a <mailbox> which he is not entitled to use. Even addresses with an
invalid <local-part> but a valid <domain> can cause disruption to the invalid <local-part> but a valid <domain> can cause disruption to the
administrators of such domains. Posters who wish to remain anonymous administrators of such domains. Posters who wish to remain anonymous
or to prevent automated harvesting of their addresses, but who do not or to prevent automated harvesting of their addresses, but who do not
care to take the additional precautions of using more sophisticated care to take the additional precautions of using more sophisticated
anonymity measures, should avoid that violation by the use of anonymity measures, should avoid that violation by the use of
addresses ending in the ".invalid" top-level-domain (see 7.5). addresses ending in the ".invalid" top-level-domain (see 7.5).
A malicious poster may also prevent his article being seen at a A malicious poster may also prevent his article being seen at a
particular site by preloading that site into the Path header (F- particular site by preloading that site into the Path header field
3.1.6) and may thus prevent the true owner of a forged From or (F-3.1.6) and may thus prevent the true owner of a forged From or
Reply-To address from ever seeing it. Reply-To address from ever seeing it.
A malicious complainer may submit a modified copy of an article (e.g. A malicious complainer may submit a modified copy of an article (e.g.
with an altered Injection-Info header) to the administrator of an with an altered Injection-Info header field) to the administrator of
injecting agent in an attempt to discredit the author of that article an injecting agent in an attempt to discredit the author of that
and even to have his posting privileges removed. Administrators article and even to have his posting privileges removed.
should therefore obtain a genuine copy of the article from their own Administrators should therefore obtain a genuine copy of the article
serving agent before taking such precipitate action. from their own serving agent before taking such precipitate action.
Administrative agencies with responsibility for establishing policies Administrative agencies with responsibility for establishing policies
in particular hierarchies can and should set bounds upon the in particular hierarchies can and should set bounds upon the
behaviour that is considered acceptable within those hierarchies (for behaviour that is considered acceptable within those hierarchies (for
example by promulgating charters for individual newsgroups, and other example by promulgating charters for individual newsgroups, and other
codes of conduct). codes of conduct).
Whilst this standard places an onus upon injecting agents to bear Whilst this standard places an onus upon injecting agents to bear
responsibility for the misdemeanours of their posters (which includes responsibility for the misdemeanours of their posters (which includes
non-adherence to established policies of the relevant hierarchies as non-adherence to established policies of the relevant hierarchies as
provided in section 7.2), and to provide assistance to the rest of provided in section 7.2), and to provide assistance to the rest of
the network by making proper use of the Injection-Info (F-3.2.13) and the network by making proper use of the Injection-Info (F-3.2.14)
Complaints-To (a-6.20) headers, it makes no provision for header field, it makes no provision for enforcement, which may in
enforcement, which may in consequence be patchy. Nevertheless, consequence be patchy. Nevertheless, injecting sites which
injecting sites which persistently fail to honour their persistently fail to honour their responsibilities or to comply with
responsibilities or to comply with generally accepted standards of generally accepted standards of behaviour are likely to find
behaviour are likely to find themselves blacklisted, with their themselves blacklisted, with their articles refused propagation and
articles refused propagation and even subject to cancellation, and even subject to cancellation, and other relaying sites would be well
other relaying sites would be well advised to withdraw peering advised to withdraw peering arrangements from them.
arrangements from them.
News Article Architecture and Protocols February 2005
8.2.2. Compromise of System Integrity 8.2.2. Compromise of System Integrity
The posting of unauthorized (as determined by the policies of the The posting of unauthorized (as determined by the policies of the
relevant hierarchy) control messages can cause unwanted newsgroups to relevant hierarchy) control messages can cause unwanted newsgroups to
be created, or wanted ones removed, from serving agents. be created, or wanted ones removed, from serving agents.
Administrators of such agents SHOULD therefore take steps to verify Administrators of such agents SHOULD therefore take steps to verify
News Article Architecture and Protocols July 2005
the authenticity of such control messages, either by manual the authenticity of such control messages, either by manual
inspection (particularly of the Approved header) or by checking any inspection (particularly of the Approved header field) or by checking
digital signatures that may be provided (see 6.1). In addition, they any digital signatures that may be provided (see 6.1). In addition,
SHOULD periodically compare the newsgroups carried against any they SHOULD periodically compare the newsgroups carried against any
regularly issued checkgroups messages, or against lists maintained by regularly issued checkgroups messages, or against lists maintained by
trusted servers and accessed by out-of-band protocols such as FTP or trusted servers and accessed by out-of-band protocols such as FTP or
HTTP. HTTP.
Malicious cancel messages (6.3) can cause valid articles to be Malicious cancel messages (6.3) can cause valid articles to be
removed from serving agents. Administrators of such agents SHOULD removed from serving agents. Administrators of such agents SHOULD
therefore take steps to verify that they originated from the therefore take steps to verify that they originated from the
(apparent) poster, the injector or the moderator of the article, or (apparent) poster, the injector or the moderator of the article, or
that in other cases they came from a place that is trusted to work that in other cases they came from a place that is trusted to work
within established policies and customs. Such steps SHOULD include within established policies and customs. Such steps SHOULD include
the checking of any digital signatures, or other security devices, the checking of any digital signatures, or other security devices,
that may be provided (see 6.1). Articles containing Supersedes that may be provided (see 6.1). Articles containing Supersedes
headers (F-3.2.5) are effectively cancel messages, and SHOULD be header fields (F-3.2.6) are effectively cancel messages, and SHOULD
subject to the same checks. Currently, many sites choose to ignore be subject to the same checks. Currently, many sites choose to
all cancel messages on account of the difficulty of conducting such ignore all cancel messages on account of the difficulty of conducting
checks. such checks.
Improperly configured serving agents can allow articles posted to Improperly configured serving agents can allow articles posted to
moderated groups onto the net without first being approved by the moderated groups onto the net without first being approved by the
moderator. Injecting agents SHOULD verify that moderated articles moderator. Injecting agents SHOULD verify that moderated articles
were received from one of the entities given in their Approved were received from one of the entities given in their Approved header
headers and/or check any digital signatures that may be provided (see fields and/or check any digital signatures that may be provided (see
6.1). 6.1).
The filename parameter of the Archive header (F-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.
[This parameter may yet be removed from USEFOR.]
There may be weaknesses in particular implementations that are There may be weaknesses in particular implementations that are
subject to malicious exploitation. In particular, it has not been subject to malicious exploitation. In particular, it has not been
unknown for complete shell scripts to be included within Control unknown for complete shell scripts to be included within Control
headers. Implementors need to be aware of this. header fields. Implementors need to be aware of this.
Reading agents should be chary of acting automatically upon MIME Reading agents should be chary of acting automatically upon MIME
objects with an "application" Content-Type that could change the objects with an "application" Content-Type that could change the
state of that agent, except in contexts where such applications are state of that agent, except in contexts where such applications are
specifically expected (as in 5). Even the Content-Type "text/html" specifically expected (as in 5). Even the Content-Type "text/html"
could have unexpected side effects on account of embedded objects, could have unexpected side effects on account of embedded objects,
especially embedded executable code or URIs that invoke non-news especially embedded executable code or URIs that invoke non-news
protocols such as HTTP [RFC 2616]. It is therefore generally protocols such as HTTP [RFC 2616]. It is therefore generally
recommended that reading agents do not enable the execution of such recommended that reading agents do not enable the execution of such
News Article Architecture and Protocols February 2005
code (since it is extremely unlikely to have a valid application code (since it is extremely unlikely to have a valid application
within Netnews) and that they only honour URIs referring to other within Netnews) and that they only honour URIs referring to other
parts of the same article. parts of the same article.
[Frank wants
MIME security considerations are discussed in [RFC2046]. Note that
applying some [RFC2231] extensions for parameters like multi-line
paramters on a boundary parameter as defined in [RFC2046] might be
abused to bypass simple algorithms trying to analyze MIME parts.]
Non-printable characters embedded in article bodies may have Non-printable characters embedded in article bodies may have
surprising effects on printers or terminals, notably by reconfiguring surprising effects on printers or terminals, notably by reconfiguring
them in undesirable ways which may become apparent only after the them in undesirable ways which may become apparent only after the
reading agent has terminated. reading agent has terminated.
News Article Architecture and Protocols July 2005
8.3. Liability 8.3. Liability
There is a presumption that a poster who sends an article to Usenet There is a presumption that a poster who sends an article to Usenet
intends it to be stored on a multitude of serving agents, and has intends it to be stored on a multitude of serving agents, and has
therefore given permission for it to be copied to that extent. therefore given permission for it to be copied to that extent.
Nevertheless, Usenet is not exempt from the Copyright laws, and it Nevertheless, Usenet is not exempt from the Copyright laws, and it
should not be assumed that permission has been given for the article should not be assumed that permission has been given for the article
to be copied outside of Usenet, nor for its permanent archiving to be copied outside of Usenet, nor for its permanent archiving
contrary to any Archive header that may be present. contrary to any Archive header field that may be present.
Posters also need to be aware that they are responsible if they Posters also need to be aware that they are responsible if they
breach Copyright, Libel, Harassment or other restrictions relating to breach Copyright, Libel, Harassment or other restrictions relating to
material that they post, and that they may possibly find themselves material that they post, and that they may possibly find themselves
liable for such breaches in jurisdictions far from their own. Serving liable for such breaches in jurisdictions far from their own. Serving
agents may also be liable in some jurisdictions, especially if the agents may also be liable in some jurisdictions, especially if the
breach has been explicitly drawn to their attention. breach has been explicitly drawn to their attention.
Users who are concerned about such matters should seek advice from Users who are concerned about such matters should seek advice from
competent legal authorities. competent legal authorities.
9. IANA Considerations 9. IANA Considerations
IANA is requested to register the following media types, described IANA is requested to register the following media types, described
elsewhere in this standard, for use with the Content-Type header, in elsewhere in this standard, for use with the Content-Type header
the IETF tree in accordance with the procedures set out in [RFC field, in the IETF tree in accordance with the procedures set out in
2048]. [RFC 2048].
application/news-transmission (5.1) application/news-transmission (5.1)
application/news-groupinfo (5.3) application/news-groupinfo (5.3)
application/news-checkgroups (5.4) application/news-checkgroups (5.4)
IANA is also requested to change the status of the following media IANA is also requested to change the status of the following media
type to "OBSOLETE". type to "OBSOLETE".
message/news (5.2) message/news (5.2)
NOTE: "Application/news-transmission" is an update, with NOTE: "Application/news-transmission" is an update, with
clarification and additional optional parameters, to an existing clarification and additional optional parameters, to an existing
registration. "Message/rfc822" should now be used in place of registration. "Message/rfc822" should now be used in place of
the obsoleted "message/news". the obsoleted "message/news".
News Article Architecture and Protocols February 2005
10. References 10. References
[To Do: Split this section into Normative and Informative references. 10.1. Normative References
This will probably be delayed until the final draft, for technical
reasons.]
[ANSI X3.4] "American National Standard for Information Systems - [ANSI X3.4] "American National Standard for Information Systems -
Coded Character Sets - 7-Bit American National Standard Code for Coded Character Sets - 7-Bit American National Standard Code for
Information Interchange (7-Bit ASCII)", ANSI X3.4, 1986. Information Interchange (7-Bit ASCII)", ANSI X3.4, 1986.
[RFC 2048] N. Freed, J. Klensin, and J. Postel, "Multipurpose
Internet Mail Extensions (MIME) Part Four: Registration
Procedures", RFC 2048, November 1996.
News Article Architecture and Protocols July 2005
[RFC 2119] S. Bradner, "Key words for use in RFCs to Indicate
Requirement Levels", RFC 2119, March 1997.
[RFC 2606] D. Eastlake and A. Panitz, "Reserved Top Level DNS Names",
RFC 2606, June 1999.
[RFC 2822] P. Resnick, "Internet Message Format", RFC 2822, April
2001.
[RFC 3864] G. Klyne, M. Nottingham, and J. Mogul, "Registration
procedures for message header fields", RFC 3864.
[USEAGE] draft-ietf-usefor-useage-*.txt.
[USEFOR] K. Murchison et al, "News Article Format", draft-ietf-
usefor-usefor-*.txt.
[USEPRO] This Standard.
10.2. Informative References
[ARTICLE] Charles H. Lindsey, "News Article Format and Transmission", [ARTICLE] Charles H. Lindsey, "News Article Format and Transmission",
draft-ietf-usefor-article-format-*.txt. draft-ietf-usefor-article-format-*.txt.
[NNTP] Clive D.W. Feather, "Network News Transport Protocol", draft- [NNTP] Clive D.W. Feather, "Network News Transport Protocol", draft-
ietf-nntpext-base-*.txt. ietf-nntpext-base-*.txt.
[PGPVERIFY] David Lawrence, [PGPVERIFY] David Lawrence,
<ftp://ftp.isc.org/pub/pgpcontrol/README.html>. <ftp://ftp.isc.org/pub/pgpcontrol/README.html>.
[RFC 1036] M. Horton and R. Adams, "Standard for Interchange of [RFC 1036] M. Horton and R. Adams, "Standard for Interchange of
USENET Messages", RFC 1036, December 1987. USENET Messages", RFC 1036, December 1987.
[RFC 1918] Y. Rekhter, B. Moskowitz, D. Karrenberg, G. J. de Groot,
and E. Lear, "Address Allocation for Private Internets", RFC
1918, February 1996.
[RFC 2045] N. Freed and N. Borenstein, "Multipurpose Internet Mail [RFC 2045] N. Freed and N. Borenstein, "Multipurpose Internet Mail
Extensions (MIME) Part One: Format of Internet Message Bodies", Extensions (MIME) Part One: Format of Internet Message Bodies",
RFC 2045, November 1996. RFC 2045, November 1996.
[RFC 2048] N. Freed, J. Klensin, and J. Postel, "Multipurpose [RFC 2046] N. Freed and N. Borenstein, "Multipurpose Internet Mail
Internet Mail Extensions (MIME) Part Four: Registration Extensions (MIME) Part Two: Media Types", RFC 2046, November
Procedures", RFC 2048, November 1996. 1996.
[RFC 2119] S. Bradner, "Key words for use in RFCs to Indicate [RFC 2142] D. Crocker, "Mailbox Names for Common Services, Roles and
Requirement Levels", RFC 2119, March 1997. Functions", RFC 2142, May 1997.
[RFC 2298] R. Fajman, "An Extensible Message Format for Message [RFC 2298] R. Fajman, "An Extensible Message Format for Message
Disposition Notifications", RFC 2298, March 1998. Disposition Notifications", RFC 2298, March 1998.
[RFC 2606] D. Eastlake and A. Panitz, "Reserved Top Level DNS Names",
RFC 2606, June 1999.
[RFC 2616] R. Fielding, J. Gettys, J. Mogul, H. Frystyk, L. Masinter, [RFC 2616] R. Fielding, J. Gettys, J. Mogul, H. Frystyk, L. Masinter,
News Article Architecture and Protocols July 2005
P. Leach, and T. Berners-Lee, "Hypertext Transfer Protocol -- P. Leach, and T. Berners-Lee, "Hypertext Transfer Protocol --
HTTP/1.1", RFC 2616, June 1999. HTTP/1.1", RFC 2616, June 1999.
[RFC 2822] P. Resnick, "Internet Message Format", RFC 2822, April [RFC 3986] T. Berners-Lee, R. Fielding, and L. Masinter, "Uniform
2001. Resource Identifier (URI): Generic Syntax", STD 66, January
2005.
[RFC 3864] G. Klyne, M. Nottingham, and J. Mogul, "Registration
procedures for message header fields", RFC 3864.
[RFC 850] Mark R. Horton, "Standard for interchange of Usenet [RFC 850] Mark R. Horton, "Standard for interchange of Usenet
messages", RFC 850, June 1983. messages", RFC 850, June 1983.
[RFC 976] Mark R. Horton, "UUCP mail interchange format standard", [RFC 976] Mark R. Horton, "UUCP mail interchange format standard",
News Article Architecture and Protocols February 2005
RFC 976, February 1986. RFC 976, February 1986.
[Son-of-1036] Henry Spencer, "News article format and transmission", [Son-of-1036] Henry Spencer, "News article format and transmission",
<ftp://ftp.zoo.toronto.edu/pub/news.txt.Z>, June 1994. <ftp://ftp.zoo.toronto.edu/pub/news.txt.Z>, June 1994.
[USEAGE] draft-ietf-usefor-useage-*.txt.
[USEFOR] C. H. Lindsey et al, "News Article Format", draft-ietf-
usefor-usefor-format-*.txt.
[USEPRO] This Standard.
11. Acknowledgements 11. Acknowledgements
TBD TBD
12. Contact Address 12. Contact Address
Editor Editor
Charles. H. Lindsey Charles. H. Lindsey
5 Clerewood Avenue 5 Clerewood Avenue
Heald Green Heald Green
Cheadle Cheadle
Cheshire SK8 3JU Cheshire SK8 3JU
United Kingdom United Kingdom
Phone: +44 161 436 6131 Phone: +44 161 436 6131
Email: chl@clw.cs.man.ac.uk Email: chl@clw.cs.man.ac.uk
[ [
Working group chair Working group chairs
Alexey Melnikov <alexey.melnikov-usefor@isode.com> Alexey Melnikov <alexey.melnikov-usefor@isode.com>
Harald Tveit Alvestrand <harald@alvestrand.no>
] ]
Comments on this draft should preferably be sent to the mailing list Comments on this draft should preferably be sent to the mailing list
of the Usenet Format Working Group at of the Usenet Format Working Group at
ietf-usefor@imc.org. ietf-usefor@imc.org.
Appendix A.1 - A-News Article Format Appendix A.1 - A-News Article Format
The obsolete "A News" article format consisted of exactly five lines The obsolete "A News" article format consisted of exactly five lines
of header information, followed by the body. For example: of header field information, followed by the body. For example:
News Article Architecture and Protocols February 2005 News Article Architecture and Protocols July 2005
Aeagle.642 Aeagle.642
news.misc news.misc
cbosgd!mhuxj!mhuxt!eagle!jerry cbosgd!mhuxj!mhuxt!eagle!jerry
Fri Nov 19 16:14:55 1982 Fri Nov 19 16:14:55 1982
Usenet Etiquette - Please Read Usenet Etiquette - Please Read
body body
body body
body body
The first line consisted of an "A" followed by an article ID The first line consisted of an "A" followed by an article ID
(analogous to a message identifier and used for similar purposes). (analogous to a message identifier and used for similar purposes).
The second line was the list of newsgroups. The third line was the The second line was the list of newsgroups. The third line was the
path. The fourth was the date, in the format above (all fields fixed path. The fourth was the date, in the format above (all fields fixed
width), resembling an Internet date but not quite the same. The fifth width), resembling an Internet date but not quite the same. The fifth
was the subject. was the subject.
This format is documented for archeological purposes only. Articles This format is documented for archaeological purposes only. Articles
MUST NOT be generated in this format. MUST NOT be generated in this format.
Appendix A.2 - Early B-News Article Format Appendix A.2 - Early B-News Article Format
The obsolete pseudo-Internet article format, used briefly during the The obsolete pseudo-Internet article format, used briefly during the
transition between the A News format and the modern format, followed transition between the A News format and the modern format, followed
the general outline of a MAIL message but with some non-standard the general outline of a MAIL message but with some non-standard
headers. For example: header fields. For example:
From: cbosgd!mhuxj!mhuxt!eagle!jerry (Jerry Schwarz) From: cbosgd!mhuxj!mhuxt!eagle!jerry (Jerry Schwarz)
Newsgroups: news.misc Newsgroups: news.misc
Title: Usenet Etiquette -- Please Read Title: Usenet Etiquette -- Please Read
Article-I.D.: eagle.642 Article-I.D.: eagle.642
Posted: Fri Nov 19 16:14:55 1982 Posted: Fri Nov 19 16:14:55 1982
Received: Fri Nov 19 16:59:30 1982 Received: Fri Nov 19 16:59:30 1982
Expires: Mon Jan 1 00:00:00 1990 Expires: Mon Jan 1 00:00:00 1990
body body
body body
body body
The From header contained the information now found in the Path The From header field contained the information now found in the Path
header, plus possibly the full name now typically found in the From header field, plus possibly the full name now typically found in the
header. The Title header contained what is now the content of the From header field. The Title header field contained what is now the
Subject header. The Posted header contained what is now the content content of the Subject header field. The Posted header field
of the Date header. The Article-I.D. header contained an article ID, contained what is now the content of the Date header field. The
analogous to a message identifier and used for similar purposes. The Article-I.D. header field contained an article ID, analogous to a
Newsgroups and Expires headers were approximately as now. The message identifier and used for similar purposes. The Newsgroups and
Received header contained the date when the latest relaying agent to Expires header fields were approximately as now. The Received header
process the article first saw it. All dates were in the above format, field contained the date when the latest relaying agent to process
with all fields fixed width, resembling an Internet date but not the article first saw it. All dates were in the above format, with
quite the same. all fields fixed width, resembling an Internet date but not quite the
same.
This format is documented for archeological purposes only. Articles This format is documented for archaeological purposes only. Articles
MUST NOT be generated in this format. MUST NOT be generated in this format.
News Article Architecture and Protocols February 2005 News Article Architecture and Protocols July 2005
Appendix A.3 - Obsolete Control Messages Appendix A.3 - Obsolete Control Messages
This present standard obsoletes certain control messages defined in This present standard obsoletes certain control messages defined in
[RFC 1036] (see 6.5), all of which had the effect of requesting a [RFC 1036] (see 6.5), all of which had the effect of requesting a
description of a relaying or serving agent's software, or its peering description of a relaying or serving agent's software, or its peering
arrangements with neighbouring sites, to be emailed to the article's arrangements with neighbouring sites, to be emailed to the article's
reply address. Whilst of some utility when Usenet was much smaller reply address. Whilst of some utility when Usenet was much smaller
than it is now, they had become no more than a tool for the malicious than it is now, they had become no more than a tool for the malicious
sending of mailbombs. Moreover, many organizations now consider sending of mailbombs. Moreover, many organizations now consider
skipping to change at page 51, line 35 skipping to change at page 52, line 35
peering arrangements. "Who gets" was similar, but restricted to a peering arrangements. "Who gets" was similar, but restricted to a
named newsgroup. "Senduuname" resembled "sendsys" but restricted to named newsgroup. "Senduuname" resembled "sendsys" but restricted to
the list of peers connected by UUCP. the list of peers connected by UUCP.
Historically, a checkgroups body consisting of one or two lines, the Historically, a checkgroups body consisting of one or two lines, the
first of the form "-n newsgroup", caused check-groups to apply to first of the form "-n newsgroup", caused check-groups to apply to
only that single newsgroup. only that single newsgroup.
Historically, an article posted to a newsgroup whose name had exactly Historically, an article posted to a newsgroup whose name had exactly
three components of which the third was "ctl" signified that article three components of which the third was "ctl" signified that article
was to be taken as a control message. The Subject header specified was to be taken as a control message. The Subject header field
the actions, in the same way the Control header does now. specified the actions, in the same way the Control header field does
now.
These forms are documented for archeological purposes only; they MUST These forms are documented for archaeological purposes only; they
NO LONGER be used. MUST NO LONGER be used.
Appendix B - Notices Appendix B - Notices
Intellectual Property Intellectual Property
The IETF takes no position regarding the validity or scope of any The IETF takes no position regarding the validity or scope of any
Intellectual Property Rights or other rights that might be claimed to Intellectual Property Rights or other rights that might be claimed to
pertain to the implementation or use of the technology described in pertain to the implementation or use of the technology described in
this document or the extent to which any license under such rights 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 might or might not be available; nor does it represent that it has
skipping to change at page 52, line 5 skipping to change at page 53, line 5
on the procedures with respect to rights in RFC documents can be on the procedures with respect to rights in RFC documents can be
found in BCP 78 and BCP 79. found in BCP 78 and BCP 79.
Copies of IPR disclosures made to the IETF Secretariat and any Copies of IPR disclosures made to the IETF Secretariat and any
assurances of licenses to be made available, or the result of an assurances of licenses to be made available, or the result of an
attempt made to obtain a general license or permission for the use of attempt made to obtain a general license or permission for the use of
such proprietary rights by implementers or users of this such proprietary rights by implementers or users of this
specification can be obtained from the IETF on-line IPR repository at specification can be obtained from the IETF on-line IPR repository at
http://www.ietf.org/ipr. http://www.ietf.org/ipr.
News Article Architecture and Protocols February 2005 News Article Architecture and Protocols July 2005
The IETF invites any interested party to bring to its attention any The IETF invites any interested party to bring to its attention any
copyrights, patents or patent applications, or other proprietary copyrights, patents or patent applications, or other proprietary
rights that may cover technology that may be required to implement rights that may cover technology that may be required to implement
this standard. Please address the information to the IETF at ietf- this standard. Please address the information to the IETF at ietf-
ipr@ietf.org. ipr@ietf.org.
Full Copyright Statement Full Copyright Statement
Copyright (C) The Internet Society (2005). This document is subject Copyright (C) The Internet Society (2005). This document is subject
skipping to change at page 52, line 34 skipping to change at page 53, line 34
INFORMATION HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED INFORMATION HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED
WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.
Appendix C - Change Log Appendix C - Change Log
[This Appendix is to be removed prior to final publication.] [This Appendix is to be removed prior to final publication.]
For version 01 For version 01
1 Numerous texts describing protocol features related to 1 Numerous texts describing protocol features related to
particular headers in parts of [ARTICLE] which were destined to particular header fields in parts of [ARTICLE] which were
become part of [USEFOR] have been moved to appropriate locations destined to become part of [USEFOR] have been moved to
within section 7 of this document. Such revised texts will be appropriate locations within section 7 of this document. Such
found in sections revised texts will be found in sections
7.2.2 Steps 4, 6, 7, 10, 11, 12; 7.2.2 Steps 4, 6, 7, 10, 11, 12;
7.2.3 Step 1(b); 7.2.3 Step 1(b);
7.3 introductory paragraphs, Steps 1, 4, 8, 9, and some final 7.3 introductory paragraphs, Steps 1, 4, 8, 9, and some final
paragraphs; paragraphs;
7.4 introductory and final paragraphs; 7.4 introductory and final paragraphs;
7.9.1 Step 5. 7.9.1 Step 5.
2 A section on "Duties of a Reading Agent" (7.8) has been added. 2 A section on "Duties of a Reading Agent" (7.8) has been added.
3 Some demotions MUST -> SHOULD -> MAY, as noted in pseudo- 3 Some demotions MUST -> SHOULD -> MAY, as noted in pseudo-
comments, have been made or proposed in sections comments, have been made or proposed in sections
7.3 7.3
7.3 Step 4. 7.3 Step 4.
4 Part of the procedure for examining Path headers by relaying 4 Part of the procedure for examining Path header fields by
agents has been moved to serving agents, as explained in relaying agents has been moved to serving agents, as explained
pseudo-comments in section 7.4. in pseudo-comments in section 7.4.
5 Some renumbering of sections and minor textual clarifications. 5 Some renumbering of sections and minor textual clarifications.
For version 02 For version 02
News Article Architecture and Protocols February 2005 News Article Architecture and Protocols July 2005
1 2nd para. of a-7 temporarily reinstated in section 6. 1 2nd para. of a-7 temporarily reinstated in section 6.
2 Para. in section 6 relating to propagation of control messages 2 Para. in section 6 relating to propagation of control messages
and local policy removed to [USEAGE].] and local policy removed to [USEAGE].]
3 Requirement for some relaying agents to examine control messages 3 Requirement for some relaying agents to examine control messages
for non-existent groups for non-existent groups
6 6
7.3 7.3
skipping to change at page 53, line 27 skipping to change at page 54, line 27
4 Text regarding "aliasing out" brought into line with actual 4 Text regarding "aliasing out" brought into line with actual
practice. practice.
7.3 7.3
5 More realistic wording regarding the expectations of reading 5 More realistic wording regarding the expectations of reading
agents agents
7.7 7.7
7.4 7.4
6 "Precursor" is now defined for all cases in which a References 6 "Precursor" is now defined for all cases in which a References
header may be used (even though "followup" is not always defined header field may be used (even though "followup" is not always
under Alternative-1). defined under Alternative-1).
2.1 2.1
7 Provision is made for a poster to use a mailbox ending in 7 Provision is made for a poster to use a mailbox ending in
".invalid" in a From header (formerly in a-5.2). ".invalid" in a From header field (formerly in a-5.2).
7.5 7.5
8 "Inheritable" and "Variant" headers defined (formerly in a- 8 "Inheritable" and "Variant" header fields defined (formerly in
4.2.5). a-4.2.5).
2.3 2.3
9 Additional wording regarding function of verb/arguments/body in 9 Additional wording regarding function of verb/arguments/body in
control messages (formerly in a-6.13). control messages (formerly in a-6.13).
6 6
10 NOTE regarding not altering message indentifiers during 10 NOTE regarding not altering message indentifiers during
transport or copying added (formerly in a-5.3). transport or copying added (formerly in a-5.3).
7.3 7.3
skipping to change at page 54, line 5 skipping to change at page 55, line 5
3.1 3.1
7.6 7.6
For version 03 For version 03
1 The term "inheritable header" is no longer defined. Instead, the 1 The term "inheritable header" is no longer defined. Instead, the
term "inherited' is used in place of "taken" when defining the term "inherited' is used in place of "taken" when defining the
actions of a followup agent. actions of a followup agent.
7.6 7.6
News Article Architecture and Protocols February 2005 News Article Architecture and Protocols July 2005
2 Consequent changes to "variant header", and also mention of 2 Consequent changes to "variant header field", and also mention
Injection-Info as sometimes variant. of Injection-Info as sometimes variant.
2.3 2.3
3 The term "reply address" is no longer defined. 3 The term "reply address" is no longer defined.
4 References now made to sections within USEFOR using "F-..." 4 References now made to sections within USEFOR using "F-..."
notation. notation.
5 Cross-references to sections within USEFOR added. Consistent use 5 Cross-references to sections within USEFOR added. Consistent use
of <...> around all mentions of syntactic objects. All of <...> around all mentions of syntactic objects. All
occurrences of "Foobar-header" changed to "Foobar header". Many occurrences of "Foobar-header" changed to "Foobar header". Many
other minor textual changes. other minor textual changes.
6 <control-message> changed to <control-command>, to avoid 6 <control-message> changed to <control-command>, to avoid
confusion with "control message", which signifies the complete confusion with "control message", which signifies the complete
article containing the <control-command>. article containing the <control-command>.
7 <ihave-arguments> has been changed to <ihave-argument> (since 7 <ihave-arguments> has been changed to <ihave-argument> (since
the earlier practice of multiple arguments is now deprecated). the earlier practice of multiple arguments is now deprecated).
Likewise <sendme-argument>. Likewise <sendme-argument>.
For version 04
1 References divided into Normative and Informational.
2 All mention of the Mail-Copies-To, Posted-And-Mailed and
Complaints-To header fields removed.
3 NOTE added to contrast MUST for References header field with
SHOULD in RFC 2822.
7.6
4 Changes arising from the new syntax of <path-delimiter>s and
<path-keyword>s.
7.3
5 Changes to clarify the construction of the References header
field.
7.6.1
6 Changes due to removal of <comment>s from further header fields.
7 New section on Identification of news-servers describing
acceptable forms for <path-identity>s.
2.3
8 Definition of "semantic content" of a header field.
2.1
9 Systematic replacement of "header" by "header field".
News Article Architecture and Protocols July 2005
10 More stringent rules for checking <newsgroup-name>s in control
messages for compliance with USEFOR.
6.2
 End of changes. 

This html diff was produced by rfcdiff 1.25, available from http://www.levkowetz.com/ietf/tools/rfcdiff/