draft-ietf-usefor-usepro-04.txt   draft-ietf-usefor-usepro-05.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
July 2005 January 2006
News Article Architecture and Protocols News Article Architecture and Protocols
<draft-ietf-usefor-usepro-04.txt> <draft-ietf-usefor-usepro-05.txt>
Status of this Memo Status of this Memo
By submitting this Internet-Draft, each author represents that any By submitting this Internet-Draft, each author represents that any
applicable patent or other IPR claims of which he or she is aware applicable patent or other IPR claims of which he or she is aware
have been or will be disclosed, and any of which he or she becomes have been or will be disclosed, and any of which he or she becomes
aware will be disclosed, in accordance with Section 6 of BCP 79. aware will be disclosed, in accordance with Section 6 of BCP 79.
.QP Internet-Drafts are working documents of the Internet .QP Internet-Drafts are working documents of the Internet
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Note that other groups may also distribute working documents as Note that other groups may also distribute working documents as
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documents at any time. It is inappropriate to use Internet-Drafts documents at any time. It is inappropriate to use Internet-Drafts
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progress." progress."
The list of current Internet-Drafts can be accessed at The list of current Internet-Drafts can be accessed at
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This Internet-Draft will expire in January 2006. This Internet-Draft will expire in July 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.
Since the 1980s, Usenet has grown explosively, and many Internet and
non-Internet sites now participate. In addition, the Netnews
technology is now in widespread use for other purposes.
Backward compatibility has been a major goal of this endeavour, but 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 Best Current Practice document [USEAGE], addressing
requirements which are present for Social rather than Normative requirements which are present for Social rather than Normative
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
News Article Architecture and Protocols January 2006
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.]
[In this draft, references to [NNTP] are to be replaced by references to [In this draft, references to [NNTP] are to be replaced by references to
the RFC arising from the series of drafts draft-ietf-nntpext-base-*.txt, the RFC arising from the series of drafts draft-ietf-nntpext-base-*.txt,
which has now passed its IETF last call.] which has now passed its IETF last call.]
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 ................................................ 4
1.3. Historical Outline ........................................ 5 1.3. Historical Outline ........................................ 5
2. Definitions, Notations and Conventions ........................ 6 2. Definitions, Notations and Conventions ........................ 5
2.1. Definitions ............................................... 6 2.1. Definitions ............................................... 5
2.2. Defining the Architecture ................................. 7 2.2. Defining the Architecture ................................. 6
2.3. Identification of news-servers ............................ 8 2.3. Identification of news servers ............................ 7
2.4. Variant Header Fields ..................................... 9 2.4. Variant Header Fields ..................................... 8
2.5. Textual Notations ......................................... 9 2.5. Textual Notations ......................................... 8
3. Changes to the existing protocols ............................. 10 3. Changes to the existing protocols ............................. 9
3.1. Principal Changes ......................................... 10 3.1. Protocol Changes .......................................... 9
3.2. Transitional Arrangements ................................. 11 3.2. Transitional Arrangements ................................. 10
4. Transport ..................................................... 12 4. Transport ..................................................... 11
5. Definition of new Media Types ................................. 13 5. Definition of new Media Types ................................. 12
5.1. Application/news-transmission ............................. 13 5.1. Application/news-transmission ............................. 12
5.2. Message/news obsoleted .................................... 14 5.2. Message/news obsoleted .................................... 13
5.3. Application/news-groupinfo ................................ 14 5.3. Application/news-groupinfo ................................ 13
5.4. Application/news-checkgroups .............................. 15 5.4. Application/news-checkgroups .............................. 14
6. Control Messages .............................................. 16 6. Control Messages .............................................. 15
6.1. Digital Signature of Header Fields ........................ 17 6.1. Digital Signature of Header Fields ........................ 16
6.2. Group Control Messages .................................... 17 6.2. Group Control Messages .................................... 16
6.2.1. The 'newgroup' Control Message ........................ 18 6.2.1. The 'newgroup' Control Message ........................ 16
6.2.1.1. The Body of the 'newgroup' Control Message ........ 18 6.2.1.1. The Body of the 'newgroup' Control Message ........ 17
6.2.1.2. Initial Articles .................................. 18 6.2.1.2. Initial Articles .................................. 17
6.2.1.3. Example ........................................... 19 6.2.1.3. Example ........................................... 18
6.2.2. The 'rmgroup' Control Message ......................... 20 6.2.2. The 'rmgroup' Control Message ......................... 19
6.2.2.1. Example ........................................... 20 6.2.2.1. Example ........................................... 19
6.2.3. The 'mvgroup' Control Message ......................... 20 6.2.3. The 'mvgroup' Control Message ......................... 19
6.2.3.1. Example ........................................... 22 6.2.3.1. Example ........................................... 21
6.2.4. The 'checkgroups' Control Message ..................... 23 6.2.4. The 'checkgroups' Control Message ..................... 21
6.3. Cancel .................................................... 24 6.3. Cancel .................................................... 23
6.4. Ihave, sendme ............................................. 25 6.4. Ihave, sendme ............................................. 23
6.5. Obsolete control messages. ............................... 26 6.5. Obsolete control messages. ............................... 25
7. Duties of Various Agents ...................................... 26 7. Duties of Various Agents ...................................... 25
7.1. General principles to be followed ......................... 27 7.1. General principles to be followed ......................... 26
7.2. Duties of an Injecting Agent .............................. 26
News Article Architecture and Protocols July 2005 7.2.1. Proto-articles ........................................ 27
7.2.2. Procedure to be followed by Injecting Agents .......... 27
News Article Architecture and Protocols January 2006
7.2. Duties of an Injecting Agent .............................. 27 7.2.3. Procedure for Forwarding to a Moderator ............... 29
7.2.1. Proto-articles ........................................ 28 7.3. Duties of a Relaying Agent ................................ 30
7.2.2. Procedure to be followed by Injecting Agents .......... 28 7.3.1. Path Header Field Example ............................. 33
7.2.3. Procedure for Forwarding to a Moderator ............... 31 7.4. Duties of a Serving Agent ................................. 34
7.3. Duties of a Relaying Agent ................................ 31 7.5. Duties of a Posting Agent ................................. 35
7.3.1. Path Header Field Example ............................. 34 7.6. Duties of a Followup Agent ................................ 36
7.4. Duties of a Serving Agent ................................. 35 7.6.1. Construction of the References header field ........... 36
7.5. Duties of a Posting Agent ................................. 36 7.7. Duties of a Reading Agent ................................. 37
7.6. Duties of a Followup Agent ................................ 37 7.8. Duties of a Moderator ..................................... 37
7.6.1. Construction of the References header field ........... 37 7.9. Duties of a Gateway ....................................... 39
7.7. Duties of a Reading Agent ................................. 38 7.9.1. Duties of an Outgoing Gateway ......................... 40
7.8. Duties of a Moderator ..................................... 38 7.9.2. Duties of an Incoming Gateway ......................... 41
7.9. Duties of a Gateway ....................................... 40 7.9.3. Example ............................................... 43
7.9.1. Duties of an Outgoing Gateway ......................... 41 8. Security and Related Considerations ........................... 44
7.9.2. Duties of an Incoming Gateway ......................... 42 8.1. Leakage ................................................... 44
7.9.3. Example ............................................... 44 8.2. Attacks ................................................... 44
8. Security and Related Considerations ........................... 45 8.2.1. Denial of Service ..................................... 44
8.1. Leakage ................................................... 45
8.2. Attacks ................................................... 45
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 ................................................. 48 8.3. Liability ................................................. 47
9. IANA Considerations ........................................... 48 9. IANA Considerations ........................................... 47
10. References ................................................... 48 10. References ................................................... 47
10.1. Normative References ..................................... 48 10.1. Normative References ..................................... 47
10.2. Informative References ................................... 49 10.2. Informative References ................................... 48
11. Acknowledgements ............................................. 50 11. Acknowledgements ............................................. 49
12. Contact Address .............................................. 50 12. Contact Address .............................................. 49
Appendix A.1 - A-News Article Format .............................. 50 Appendix A - Obsolete Control Messages ............................ 49
Appendix A.2 - Early B-News Article Format ........................ 51 Appendix B - Notices .............................................. 50
Appendix A.3 - Obsolete Control Messages .......................... 52 Appendix C - Change Log ........................................... 51
Appendix B - Notices .............................................. 52 News Article Architecture and Protocols January 2006
Appendix C - Change Log ........................................... 53
News Article Architecture and Protocols July 2005
[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
certain amount of material - basic concepts, definitions, etc - which
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
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
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
(the "Primary") should contain it and which one should incorporate it by
reference (essentially, this draft is written so that it could be the
Primary).]
1. Introduction 1. Introduction
1.1. Basic Concepts 1.1. Basic Concepts
"Netnews" is a set of protocols for generating, storing and "Netnews" is a set of protocols for generating, storing and
retrieving news "articles" (which resemble email messages) and for retrieving news "articles" (which resemble email messages) and for
exchanging them amongst a readership which is potentially widely exchanging them amongst a readership which is potentially widely
distributed. It is organized around "newsgroups", with the distributed. It is organized around "newsgroups", with the
expectation that each reader will be able to see all articles posted expectation that each reader will be able to see all articles posted
to each newsgroup in which he participates. These protocols most to each newsgroup in which he participates. These protocols most
commonly use a flooding algorithm which propagates copies throughout commonly use a flooding algorithm which propagates copies throughout
a network of participating servers. Typically, only one copy is a network of participating servers. Typically, only one copy is
stored per server, and each server makes it available on demand to stored per server, and each server makes it available on demand to
readers able to access that server. readers able to access that server.
An important characteristic of Netnews is the lack of any requirement
for a central administration or for the establishment of any
controlling host to manage the network. A set of hosts within a
network which, by mutual arrangement, operates some variant (whether
more or less restrictive) of the Netnews protocols is a "cooperating
subnet".
"Usenet" is a particular worldwide publicly accessible network based "Usenet" is a particular worldwide publicly accessible network based
upon the Netnews protocols, with the newsgroups being organized into upon the Netnews protocols, with the newsgroups being organized into
recognized "hierarchies". Anybody can join (it is simply necessary recognized "hierarchies". Anybody can join (it is simply necessary
to negotiate an exchange of articles with one or more other to negotiate an exchange of articles with one or more other
participating hosts). participating hosts).
An important characteristic of Usenet is the lack of any requirement
for a central administration or for the establishment of any
controlling host to manage the network. Nevertheless, administrative
agencies do exists with varying degrees of authority to establish
"policies" applicable to particular parts of Usenet.
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.
[Could omit that last sentence.]
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 individual sections in the companion [USEFOR]
prefixed with "F-". are prefixed with "F-".
A set of hosts within a network which, by mutual arrangement,
operates some variant (whether more or less restrictive) of the
Netnews protocols is a "cooperating subnet".
[It is not clear whether we still need that definition.]
News Article Architecture and Protocols January 2006
It is NOT the purpose of this standard to settle matters of policy, It is NOT the purpose of this standard to settle matters of policy,
nor aspects of software behaviour which do not impinge upon the nor aspects of software behaviour which do not impinge upon the
generation, transmission, storage and reception of articles, nor how generation, transmission, storage and reception of articles, nor how
the authority of various agencies to create such policies and to the authority of various agencies to create such policies and to
exercise control or oversight of the various parts of Usenet is exercise control or oversight of the various parts of Usenet is
established. For these purposes, a separate Best Current Practice established. For these purposes, a separate Best Current Practice
document [USEAGE] is being provided. document [USEAGE] is being provided.
Nevertheless, it is assumed that such agencies with the necessary Nevertheless, it is assumed that such agencies with the necessary
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their use. their use.
1.3. Historical Outline 1.3. Historical Outline
Network news originated as the medium of communication for Usenet, Network news originated as the medium of communication for Usenet,
circa 1980. Since then, Usenet has grown explosively, and many circa 1980. Since then, Usenet has grown explosively, and many
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 For an account of the earlier formats used in Netnews prior to [RFC
format. Shortly thereafter, an article format vaguely resembling 1036], see Henry Spencer's 1994 draft, popularly referred to as "Son
Internet Mail was devised and used briefly. Both of those formats of 1036" [Son-of-1036], which has recently been republished as an
are completely obsolete; they are documented in Appendix A.1 and Informational RFC.
Appendix A.2 for historical reasons only. With publication of [RFC [That is a tentative statement, which may need revision.]
850] in 1983, news articles came to closely resemble Internet Mail
messages, with some restrictions and some additional header fields.
[RFC 1036] in 1987 updated [RFC 850] without making major changes.
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
1036, and it is hoped that we have followed its spirit and
intentions.
[It is anticipated that [Son-of-1036] will shortly be published as an
informational RFC (for purposes of historical documentation only), in
which case most historical information can be removed from this draft,
including the whole of Appendix A.1 and Appendix A.2.]
News Article Architecture and Protocols July 2005 Although never adopted as a formal standard, [Son-of-1036] had a
considerable effect on the development of Netnews and hence on these
present standards, and it is hoped that we have followed its spirit
and intentions.
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] All the technical terms defined in F-1.5 are to be considered as
"message". A "proto-article" is one that has not yet been injected defined also, with the same meaning, in this standard. In addition,
into the news system. In constrast to an article, a proto- article some further terms are defined here, and in the following section.
may lack some mandatory header fields
A "message identifier" (F-3.1.3) is a unique identifier for an
article, usually supplied by the posting agent which posted it or,
failing that, by the injecting agent. It distinguishes the article
from every other article ever posted anywhere. Articles with the same
message identifier are treated as if they are the same article
regardless of any differences in the body or header fields.
A "newsgroup" is a single news forum, a logical bulletin board,
having a name and nominally intended for articles on a specific
topic. An article is "posted to" a single newsgroup or several
newsgroups. When an article is posted to more than one newsgroup, it
is said to be "crossposted"; note that this differs from posting the
same text as part of each of several articles, one per newsgroup.
A newsgroup may be "moderated", in which case submissions are not
posted directly, but mailed to a "moderator" for consideration and
possible posting. Moderators are typically human but may be
implemented partially or entirely in software.
A "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
used where several initial components are shared. also used where several initial components are shared.
A "poster" is the person or software that composes and submits a
possibly compliant article for submission to a posting agent. The
poster is analogous to [RFC 2822]'s author.
A "reader" is the person or software reading news articles.
A "followup" is an article containing a response to the contents of
an earlier article, its "precursor". Every followup includes a
References header field identifying that precursor (but note that
non-followup articles may also use a References header field).
An (email) "address" is the mailbox [RFC 2822] (or more particularly
the addr-spec within that mailbox) which directs the delivery of an
email to its intended recipient, who is said to "own" that address.
A "sender" is the person or software (usually, but not always, the
same as the poster) responsible for the operation of the posting
agent or, which amounts to the same thing, for passing the article to
the injecting agent.
[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
control information; a "serving agent" (and in some cases a "relaying
agent") receiving such an article may (subject to the policies
observed at that site) take actions beyond just filing and passing on
the article.
The "semantic content" (often abbreviated to just "content" when the The "semantic content" (often abbreviated to just "content" when the
context is clear) of a header field is its semantic interpretation; context is clear) of a header field is its semantic interpretation;
i.e. what remains after unfolding it and removing its field name with 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 its colon and any leading and trailing whitespace and, in the case of
structured header fields only, ignoring comments and other structured header fields only, ignoring comments and other
semantically invisible items and replacing white space by a single semantically invisible items and replacing white space by a single
SP. SP.
News Article Architecture and Protocols January 2006
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 header fields defined wherever stored, are identical apart from those header fields defined
as variant (2.4). as variant (2.4). For explaining the working of the protocols, it is
convenient to define particular sub-categories of agent as follows:
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.
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and passes it on to a "relaying agent" for general distribution. and passes it on to a "relaying agent" for general distribution.
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.
[There is a suggestion that "serving agent" should be changed to
"storage agent" throughout.]
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) together
collectively as "user agents". comprise the "user agents" defined in F-1.5.
Injecting, relaying and serving agents (which are often just News Article Architecture and Protocols January 2006
different services provided by the same piece of software) are known
collectively as "news-servers".
2.3. Identification of news-servers Likewise, injecting, relaying and serving agents (which are often
just different services provided by the same piece of software)
together comprise the "news servers".
News-servers need to identify themselves by inserting their public 2.3. Identification of news servers
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- [The format of the Path header is still under discussion (ticket #1047).
identity>, but some of them are less suited to providing a unique Hence the following texts are tentative, and will need to be changed (as
identity for the news-server concerned and are NOT RECOMMENDED, as will the associated protocols in 7.3). Moreover, there are two
shown: alternative texts which have been proposed:]
1. A fully qualified domain name (FQDN) associated with an "A" or In order to record the passage of articles through the network, news
"AAAA" record (or an equivalent "CNAME"), which SHOULD identify servers need to identify themselves by means of a <path-identity>
the actual host inserting this <path-identity> and, ideally, (F-3.1.6), which can appear in Path, Injection-Info and Xref header
should also be "mailable" (see below). fields. Whatever <path-identity> is used in the Path header field
SHOULD be used also in any Injection-Info header field (and it would
be normal to use it in any Xref header field also).
[Maybe that last sentence moves elsewhere.]
2. An encoding of an IP address - <IPv4address> or <IPv6address> [RFC NOTE: Such <path-identity>s may also be suitable for sending
3986] - which SHOULD be a publicly recognized address [RFC 1918] email to news server administrators (see [USEAGE]).
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" [1st alternative]
record, which MUST be "mailable".
4. Some other (arbitrary) name believed to be unique and registered <Path-identity>s can take the following forms (in decreasing order of
preference):
1. 1. A fully qualified domain name (FQDN) that SHOULD be resolvable
in the DNS (whether via an A, AAAA or MX record or an equivalent
CNAME), thus guaranteeing a unique identity. Ideally, it will also
provide a means to contact the administrators by email (according
to [RFC 2142], the forms "usenet@server" and "news@server" are
common addresses for a news server administrator).
2. Some other (arbitrary) name believed to be unique and registered
at least with all other news servers sending articles directly to
the given one. This option SHOULD NOT be used unless the earlier
option is unavailable (e.g. because the server in question is not
connected to the Internet), or unless it is of longstanding usage
and cessation would be unduly disruptive, or unless the earlier
option is provided as well.
[2nd alternative]
<Path-identity>s can take the following forms (in decreasing order of
preference):
1. A fully qualified domain name (FQDN) that can be resolved to an
email server via an MX, A or AAAA record according to the
procedures of [RFC 2821]; this guarantees that the name is unique,
and makes it easy to contact the administrators if needed.
News Article Architecture and Protocols January 2006
2. A fully qualified domain name (FQDN) that is guaranteed to be
unique by the administrators of the domain; for instance, the
uniqueness of "server.example.org" could be guaranteed by the
administrator of "example.org" even if nothing is stored in the
DNS for that name.
3. Some other (arbitrary) name believed to be unique and registered
at least with all other news-servers sending articles directly to at least with all other news-servers sending articles directly to
the given one. The news-server administrator is responsible for the given one. This option SHOULD NOT be used unless the earlier
choosing an appropriate name (and will bear the consequences of an options are unavailable, or unless the name is of longstanding
inappropriate choice). This option SHOULD NOT be used unless the usage and cessation would be unduly disruptive, or unless one of
earlier options are unavailable (e.g. because the host in question the earlier options is provided as well.
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 According to [RFC 2142]], the forms "usenet@server" and "news@server"
are common addresses for a news server administrator.
[end of alternatives]
NOTE: A news server administrator who chooses a name which turns
out not to be unique will have to bear the consequences.
NOTE: The syntax permits the colon character (which, prior to NOTE: The syntax permits the colon character (which, prior to
this standard, was a <path-delimiter>) within any <path- this standard, was a <path-delimiter>) within any <path-
identity> which is in the form of an <IPv6address>. It would identity> which is in the form of an <IPv6address>. It would
therefor be unwise to choose, as such a name, anything composed therefore be unwise to choose, as such a name, anything composed
solely from four (or less) hexadecimal digits. 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 2.4. Variant Header Fields
Header fields with the variant property may differ between (or even Header fields with the variant property may differ between (or even
be completely absent from) copies of the same article as stored or 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 header fields are modified as articles are Typically, these header fields are modified as articles are
propagated, or they reflect the status of the article on a particular propagated, or they reflect the status of the article on a particular
serving agent, or cooperating group of such agents. A variant header serving agent, or cooperating group of such agents. A variant header
field MAY be placed anywhere within the header fields (though placing field MAY be placed anywhere within the header fields (though placing
skipping to change at page 9, line 53 skipping to change at page 9, line 5
special situations involving reinjection (7.2 and 7.2.2). special situations involving reinjection (7.2 and 7.2.2).
2.5. Textual Notations 2.5. Textual Notations
This standard contains explanatory NOTEs using the following format. This standard contains explanatory NOTEs using the following format.
These may be skipped by persons interested solely in the content of These may be skipped by persons interested solely in the content of
the specification. The purpose of the notes is to explain why choices the specification. The purpose of the notes is to explain why choices
were made, to place them in context, or to suggest possible were made, to place them in context, or to suggest possible
implementation techniques. implementation techniques.
News Article Architecture and Protocols January 2006
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].
NOTE: The use of "MUST" or "SHOULD" implies a requirement that
would or could lead to interoperability problems if not
followed.
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
skipping to change at page 10, line 45 skipping to change at page 9, line 49
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
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 (3.2), though some of the new features may not begin to show benefit
they become widely implemented. This section summarizes the main until they become widely implemented. Changes in the syntax and
changes, and comments on some features of the transition. format are documented in F-Appendix B and changes to control messages
and the protocols are documented below.
3.1. Principal Changes
o The [RFC 2822] conventions for parenthesis-enclosed <comment>s in
header fields are supported in all newly defined header fields
and in header fields inherited from [RFC 2822]. They are,
however, still disallowed for performance and/or compatibility
reasons in the Message-ID, Newsgroups, Path, Followup-To,
Control, Supersedes, Distribution, Xref and Lines header fields.
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 3.1. Protocol Changes
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 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 field to o Certain Control messages (Appendix A) have been made obsolete,
facilitate the rejection of stale articles. and the special significance of "cmsg" when at the start of a
o There are new optional header fields defined, Archive, News Article Architecture and Protocols January 2006
Injection-Info and User-Agent, leading to increased
functionality. Subject header field has been removed (section 6).
o Certain header fields and Control messages (F-3.3 and Appendix o Additional media types are defined for better structuring of
A.3) have been made obsolete. control messages (5.3 and 5.4).
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 news servers, which are
agents, which are responsible for the distribution and storage of responsible for the distribution and storage of news articles, and
news articles, and user agents, which are responsible for user agents, which are responsible for interactions with users. It is
interactions with users. It is important that the former should be important that the former should be upgraded to conform to this
upgraded to conform to this standard as soon as possible to provide standard as soon as possible to provide the benefit of the enhanced
the benefit of the enhanced facilities. Fortunately, the number of facilities. Fortunately, the number of distinct implementations of
distinct implementations of such agents is rather small, at least so such servers is rather small, at least so far as the main "backbone"
far as the main "backbone" of Usenet is concerned, and many of the of Usenet is concerned, and many of the new features are already
new features are already supported. Contrariwise, there are a great supported. Contrariwise, there are a great number of implementations
number of implementations of user agents, installed on a vastly of user agents, installed on a vastly greater number of small sites.
greater number of small sites. Therefore, the new functionality has Therefore, the new functionality has been designed so that existing
been designed so that existing user agents may continue to be used, user agents may continue to be used, although the full benefits may
although the full benefits may not be realised until a substantial not be realised until a substantial proportion of them have been
proportion of them have been upgraded. 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 header fields do not affect o [RFC 2822] style <comment>s have been prohibited in the case of
serving and relaying agents. They are unlikely to hinder their those header fields of particular concern to news servers. They
proper display in existing reading agents except in the case of are 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 field in
Therefore, it is provided that they SHOULD NOT be generated in agents which thread articles. [USEFOR] therefore provides that
that case. they SHOULD NOT be generated in that case.
o Because of its importance to all serving agents, the newly o Because of its importance to all serving agents, the whitespace
permitted whitespace and folding in Newsgroups header fields and folding in Newsgroups header fields newly permitted by
SHOULD NOT be generated (though it MUST be accepted); this [USEFOR] SHOULD NOT be generated (though it MUST be accepted);
restriction may well be removed in a future version of this this restriction may well be removed in a future version of this
standard. standard.
[That last bit needs discussion. It should probably be moved to USEFOR
if it is to be retained.]
o The new style of Path header field, using "!!" as a <path- o The new style of Path header field, using "!!" as a <path-
delimiter>, is already consistent with the previous standards. delimiter>, is already consistent with the previous standards.
However, the intention is that relaying agents should eventually However, the intention is that relaying agents should eventually
reject articles in the old style, and so this possibility should reject articles in the old style, and so this possibility should
be offered as a configurable option in relaying agents. User be offered as a configurable option in relaying agents. User
News Article Architecture and Protocols July 2005
agents are unaffected. agents are unaffected.
o The introduction of MIME reflects a practice that is already o The introduction by [USEFOR] of MIME reflects a practice that is
widespread. Articles in strict compliance with the previous already widespread. Articles in strict compliance with the
standards (using strict US-ASCII) will be unaffected. Many user previous standards (using strict US-ASCII) will be unaffected.
agents already support it, at least to the extent of widely used Many user agents already support it, at least to the extent of
charsets such as ISO-8859-1. Users expecting to read articles widely used charsets such as ISO-8859-1. Users expecting to read
using other charsets will need to acquire suitable reading articles using other charsets will need to acquire suitable
agents. It is not intended, in general, that any single user reading agents. It is not intended, in general, that any single
agent will be able to display every charset known to IANA, but News Article Architecture and Protocols January 2006
all such agents MUST support US-ASCII. Serving and relaying
user agent will be able to display every charset known to IANA,
but 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 field in the case of articles injected through existing header field in the case of articles injected through existing
agents which do not yet provide an Injection-Date header field. agents which do not yet provide an Injection-Date header field.
o All the header fields newly introduced by this standard can o All the header fields newly introduced by [USEFOR] can safely be
safely be ignored by existing software, albeit with loss of the ignored by existing software, albeit with loss of the new
new functionality. 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.
skipping to change at page 13, line 4 skipping to change at page 11, line 52
Transfer-Encoding such as base64. Transfer-Encoding such as base64.
In particular, transmission paths MUST convey all header fields In particular, transmission paths MUST convey all header fields
(including body part header fields and header fields within (including body part header fields and header fields within
message/rfc822 objects) intact, even if they contain octets in the message/rfc822 objects) intact, even if they contain octets in the
range 128 to 255. Furthermore, relaying agents MUST, and other range 128 to 255. Furthermore, relaying agents MUST, and other
agents SHOULD, convey lines even if they exceed 998 characters in agents SHOULD, convey lines even if they exceed 998 characters in
length, especially in article bodies. These requirements include the length, especially in article bodies. These requirements include the
transmissiom paths between posting agents, injecting agents, relaying transmissiom paths between posting agents, injecting agents, relaying
agents, serving agents and reading agents, but NOT the paths 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 traversed by Netnews articles that have been gatewayed into Email
(7.9.1). (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.]
News Article Architecture and Protocols January 2006
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
skipping to change at page 14, line 4 skipping to change at page 12, line 55
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.
News Article Architecture and Protocols January 2006
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.
5.2. Message/news obsoleted 5.2. Message/news obsoleted
The Media Type "message/news", as previously registered with IANA, is The Media Type "message/news", as previously registered with IANA, is
hereby declared obsolete. It was never widely implemented, and its hereby declared obsolete. It was never widely implemented, and its
default treatment as "application/octet-stream" by agents that did default treatment as "application/octet-stream" by agents that did
not recognize it was counter productive. The Media Type not recognize it was counter productive. The Media Type
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Security considerations: this type MUST NOT be used except as part Security considerations: this type MUST NOT be used except as part
of a control message for the creation or of a control message for the creation or
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:"
News Article Architecture and Protocols January 2006
newsgroups-line = newsgroup-name newsgroups-line = newsgroup-name
[ 1*HTAB newsgroup-description ] [ 1*HTAB newsgroup-description ]
[ 1*WSP moderation-flag ] [ 1*WSP moderation-flag ]
newsgroup-description newsgroup-description
= utext *( *WSP utext ) = utext *( *WSP utext )
moderation-flag = %x28.4D.6F.64.65.72.61.74.65.64.29 moderation-flag = %x28.4D.6F.64.65.72.61.74.65.64.29
; case sensitive "(Moderated)" ; case sensitive "(Moderated)"
The <newsgroup-description> MUST NOT contain any occurrence of the The <newsgroup-description> MUST NOT contain any occurrence of the
string "(Moderated)" within it. Although optional, the <newsgroups- string "(Moderated)" within it. Although optional, the <newsgroups-
skipping to change at page 16, line 5 skipping to change at page 14, line 55
MIME type name: application MIME type name: application
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:
News Article Architecture and Protocols January 2006
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
skipping to change at page 17, line 5 skipping to change at page 15, line 56
ending in ".ctl" in the Newsgroups header field caused the Subject ending in ".ctl" in the Newsgroups header field caused the Subject
header field content (not starting with "cmsg" in this case) to be header field content (not starting with "cmsg" in this case) to be
interpreted as a <control-command>. interpreted as a <control-command>.
All these practices, which have already largely fallen into disuse, All these practices, which have already largely fallen into disuse,
are now declared to be Obsolete, and Subject header fields MUST NOT are now declared to be Obsolete, and Subject header fields MUST NOT
now be interpreted as <control-command>s under any circumstances. now be interpreted as <control-command>s under any circumstances.
[Possible addtional text:] [Possible addtional text:]
News Article Architecture and Protocols July 2005
In order to prevent continuing interpretation of Subject header In order to prevent continuing interpretation of Subject header
fields in this way by existing agents, posting and injecting agents fields in this way by existing agents, posting and injecting agents
SHOULD detect and decline to post articles in which the Subject SHOULD detect and decline to post articles in which the Subject
header field starts with the word "cmsg" and in which there is no header field starts with the word "cmsg" and in which there is no
Control header field. Control header field.
News Article Architecture and Protocols January 2006
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 Header Fields 6.1. Digital Signature of Header Fields
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conformance before honouring them. conformance before honouring them.
All of the group control messages MUST have an Approved header field All of the group control messages MUST have an Approved header field
(F-3.2.9) which, in those hierarchies where appropriate (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 any 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
[USEAGE]. [USEAGE].
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 = FWS newsgroup-name [ FWS newgroup-flag ] Newgroup-arguments = FWS newsgroup-name [ FWS newgroup-flag ]
newgroup-flag = "moderated" newgroup-flag = "moderated"
News Article Architecture and Protocols January 2006
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.
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field will be needed, and each separate part will then need its own field will be needed, and each separate part will then need its own
Content-Type header field. 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 field 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
News Article Architecture and Protocols January 2006
Message-ID header field, the message identifier in it MUST be Message-ID header field, the message identifier in it MUST be
different from that of any existing article and from that of the different from that of any existing article and from that of the
control message as a whole. Alternatively such a message identifier control message as a whole. Alternatively such a message identifier
MAY be derived by the injecting agent when the proto-article is MAY be derived by the injecting agent when the proto-article is
posted. The proto-article SHOULD include the header field posted. The proto-article SHOULD include the header field
"Distribution: local". "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
skipping to change at page 20, line 4 skipping to change at page 18, line 49
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 January 2006
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
skipping to change at page 21, line 5 skipping to change at page 19, line 48
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 = FWS newsgroup-name FWS newsgroup-name Mvgroup-arguments = FWS newsgroup-name FWS newsgroup-name
[ FWS 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 January 2006
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 22, line 4 skipping to change at page 20, line 48
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,
News Article Architecture and Protocols July 2005
their Newsgroups header fields MUST contain exactly those newsgroups 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
field (F-3.2.11) 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 January 2006
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 23, line 4 skipping to change at page 21, line 47
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 January 2006
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*( FWS ["!"] newsgroup-name ) chkscope = 1*( FWS ["!"] newsgroup-name )
chksernr = FWS "#" 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
skipping to change at page 24, line 5 skipping to change at page 22, line 45
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 January 2006
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 = FWS msg-id [FWS] 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
skipping to change at page 25, line 4 skipping to change at page 23, line 43
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 header fields of the "cancel" message should match those Sender header fields of the "cancel" message should match those
of the original article has been removed from this standard, of the original article has been removed from this standard,
News Article Architecture and Protocols July 2005
since it only encouraged cancel issuers to conceal their true since it only encouraged cancel issuers to conceal their true
identity, and it was not usually checked or enforced by identity, and it was not usually checked or enforced by
canceling software. Therefore, both the From and/or Sender canceling software. Therefore, both the From and/or Sender
header fields and any Approved header field should now relate to header fields and any Approved header field should now relate to
the entity responsible for issuing the "cancel" message. 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 January 2006
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 F-3.1.6 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.
The "ihave" message states that the named relaying agent has received The "ihave" message states that the named relaying agent has received
articles with the specified message identifiers, which may be of articles with the specified message identifiers, which may be of
interest to the relaying agents receiving the ihave message. The interest to the relaying agents receiving the ihave message. The
"sendme" message requests that the agent receiving it send the "sendme" message requests that the agent receiving it send the
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 January 2006
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
field of the form "to." followed by one (or possibly more) field of the form "to." followed by one (or possibly more)
<component>s in the form of a <relayer-name> (see section F-3.1.5 <component>s in the form of a <relayer-name> (see section F-3.1.5
which forbids "to" as the first <component> of a <newsgroup-name>). which forbids "to" as the first <component> of a <newsgroup-name>).
The control message SHOULD then be delivered ONLY to the relaying The control message SHOULD then be delivered ONLY to the relaying
agent(s) identified by that <relayer-name>, and any relaying agent agent(s) identified by that <relayer-name>, and any relaying agent
receiving such a message which includes its own <relayer-name> MUST receiving such a message which includes its own <relayer-name> MUST
NOT propagate it further. Each pair of relaying agent(s) sending and NOT propagate it further. Each pair of relaying agent(s) sending and
receiving these messages MUST be immediate neighbours, exchanging receiving these messages MUST be immediate neighbours, exchanging
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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.
The following control messages (as described in Appendix A.3) are The following control messages (as described in Appendix A) are
declared obsolete by this standard: declared obsolete by this standard:
sendsys sendsys
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 January 2006
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
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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]. It that any article it injects conforms with the rules of [USEFOR]. It
is also expected to bear some responsibility towards the rest of the is also expected to bear some responsibility towards the rest of the
network for the behaviour of its posters (and provision is therefore network for the behaviour of its posters.
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 field, an Injection-Info header presence of an Injection-Date header field, an Injection-Info header
field, or more than one "POSTED" in a Path header field) it MAY field, or more than one "POSTED" in a Path header field) it MAY
News Article Architecture and Protocols July 2005
choose to reject it, but otherwise SHOULD cause it to be relayed, as choose to reject it, but otherwise SHOULD cause it to be relayed, as
it stands, by a relaying agent (7.3). 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, 7
7 and 9). News Article Architecture and Protocols January 2006
and 9).
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
skipping to change at page 29, line 5 skipping to change at page 27, line 45
between the posting agent and the injecting agent proper. between the posting agent and the injecting agent proper.
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 header fields where required, followup agents. It verifies them, adds header fields where required,
and then either forwards them to a moderator or injects them by and then either forwards them to a moderator or injects them by
passing them to serving or relaying agents. It MUST NOT forward an passing them to serving or relaying agents. It MUST NOT forward an
already 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 header field already present 1. It MUST remove any Injection-Info header field already present
(though it might be useful to copy it to a suitable "X-" header (though it might be useful to copy it to a suitable "X-" header
field). It SHOULD likewise remove any NNTP-Posting-Host, X-Trace, field). It SHOULD likewise remove any NNTP-Posting-Host, X-Trace,
or other non-standard tracing header field. 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 header fields contain unverified MAY reject articles in which header fields contain unverified
email addresses, that is, addresses which are not known to be email addresses, that is, addresses which are not known to be
valid for the trusted source, though it would be perverse to valid for the trusted source, though it would be perverse to
reject intentionally unverifiable addresses such as those ending reject intentionally unverifiable addresses such as those ending
in ".invalid" (7.5). in ".invalid" (7.5).
News Article Architecture and Protocols January 2006
3. It SHOULD reject any article whose Date header field (F-3.1.2) is 3. It SHOULD reject any article whose Date header field (F-3.1.2) is
more than 24 hours into the future (and MAY use a margin less than more than 24 hours into the future (and MAY use a margin less than
that 24 hours). It MUST (except when reinjecting) reject any that 24 hours). It MUST (except when reinjecting) reject any
article with an Injection-Date header field already present (and article with an Injection-Date header field already present (and
SHOULD do likewise with any NNTP-Posting-Date header field). When SHOULD do likewise with any NNTP-Posting-Date header field). When
reinjecting it MAY, in the absence of any Injection-Date header reinjecting it MAY, in the absence of any Injection-Date header
field, reject any article whose Date header field appears to be field, reject any article whose Date header field appears to be
stale (e.g. more than 72 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
header fields for a proto-article (except, when reinjecting, for header fields for a proto-article or which contains any header
the Injection-Date header field), or which contains any header
field that does not have legal contents. It SHOULD reject any field that does not have legal contents. It SHOULD reject any
article which contains any header field deprecated for Netnews article which contains any header field deprecated for Netnews
(e.g. as in [RFC 2298]). It SHOULD reject any article whose (e.g. as in [RFC 2298]). It SHOULD reject any article whose
Newsgroups header field does not contain at least one <newsgroup- Newsgroups header field does not contain at least one <newsgroup-
name> for an existing group (as listed by its associated serving name> for an existing group (as listed by its associated serving
agent) and it MAY reject any <newsgroup-name> which violates one agent) and it MAY reject any <newsgroup-name> which violates one
of the restrictions in F-3.1.5 or which, although otherwise of the restrictions in F-3.1.5 or which, although otherwise
correct, violates a policy restriction established, for some correct, violates a policy restriction established, for some
(sub-)hierarchy, by an agency with the appropriate authority (sub-)hierarchy, by an agency with the appropriate authority
(1.2). Observe that crossposting to unknown newsgroups is not (1.2). Observe that crossposting to unknown newsgroups is not
skipping to change at page 30, line 4 skipping to change at page 28, line 46
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 header fields (with appropriate 6. The Message-ID, Date and From header fields (with appropriate
contents) MUST be added when not already present. A User-Agent contents) MUST be added when not already present. A User-Agent
header field MAY be added (or an already present User-Agent header header field MAY be added (or an already present User-Agent header
field MAY be augmented) so as to identify the software (e.g. field MAY be augmented) so as to identify the software (e.g.
"INN/1.7.2") used by the injecting agent. "INN/1.7.2") used by the injecting agent.
[That last sentence may need to be reconsidered (in which case see
News Article Architecture and Protocols July 2005 consequential change in 7.3).]
NOTE: The Message-ID, Date and From fields will already be 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 header fields not already (except when reinjecting) add other header fields not already
provided by the poster, but SHOULD NOT alter, delete, or reorder provided by the poster, but SHOULD NOT alter, delete, or reorder
any existing header field, with the specific exception of the any existing header field, with the specific exception of the
"tracing" header field Injection-Info, which is to be removed as "tracing" header field Injection-Info, which is to be removed as
already mentioned. already mentioned.
News Article Architecture and Protocols January 2006
8. If the Newsgroups header field contains one or more moderated 8. If the Newsgroups header field contains one or more moderated
groups and the article does NOT contain an Approved header field, groups and the article does NOT contain an Approved header field,
the injecting agent MUST forward it to a moderator as specified in the injecting agent MUST forward it to a moderator as specified in
section 7.2.3 below. section 7.2.3 below.
9. Otherwise, a Path header field with a <tail-entry> (F-3.1.6) MUST 9. Otherwise, a Path header field with a <tail-entry> (F-3.1.6) MUST
be correctly added if not already present. During reinjection, the be correctly added if not already present. During reinjection, the
existing Path header field 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,
followed by a '!', the <path-keyword> "POSTED" and a further "!" followed by a '!', the <path-keyword> "POSTED" and a further "!"
(or "!!" if appropriate) to the content of the Path header field; (or "!!" if appropriate) to the content of the Path header field;
this header field SHOULD then be folded if it would otherwise this header field SHOULD then be folded if it would otherwise
result in a header line of excessive length. The prepended result in a header line of excessive length.
<path-identity> MUST be an FQDN mailable address (2.3). [This may need further changes depending on the resolution of ticket
#1047.]
NOTE: This could result in more that one "POSTED" <path-keyword> NOTE: This could result in more that one "POSTED" <path-keyword>
in the case of reinjection. in the case of reinjection.
11.An Injection-Info header field (F-3.2.14) SHOULD be added, 11.An Injection-Info header field (F-3.2.14) SHOULD be added,
identifying the trusted source of the article and possibly an identifying the trusted source of the article and possibly an
address for mailing complaints to. Each injecting agent SHOULD address for mailing complaints to. Each injecting agent SHOULD
use a consistent form of the Injection-Info header field for all use a consistent form of the Injection-Info header field for all
articles emanating from the same or similar origins. articles emanating from the same or similar origins.
skipping to change at page 31, line 4 skipping to change at page 29, line 51
(F-3.2.1) 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 field (and delete, an already present Injection-Date header field (and
likewise SHOULD NOT alter, or delete, an already present NNTP- likewise SHOULD NOT alter, or delete, an already present NNTP-
Posting-Date header field). Finally, it forwards the article to Posting-Date header field). Finally, it forwards the article to
one or more relaying or serving agents, and the injection process one or more relaying or serving agents, and the injection process
is to be considered 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 field is to be created It follows that it MUST NOT header field is to be created It follows that it MUST NOT
subsequently be replaced, changed or deleted by any other agent, subsequently be replaced, changed or deleted by any other agent,
News Article Architecture and Protocols July 2005
even during reinjection. 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 an 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 field, customarily moderated group listed in the Newsgroups header field, customarily
via email, (see 7.8 for how that moderator may forward it to via email, (see 7.8 for how that moderator may forward it to
further moderators). There are two possibilities for doing this: further moderators). There are two possibilities for doing this:
News Article Architecture and Protocols January 2006
(a) The complete article is encapsulated (header fields and all) (a) The complete article is encapsulated (header fields and all)
within 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 header fields, or of conflict between Netnews and Email header fields, or of
changes to those fields 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
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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 field and at least of the <newsgroup-name>s in its Newsgroups header field and at least
one of the <dist-name>s in its Distribution header field, if any. one of the <dist-name>s in its Distribution header field, if any.
Exceptionally, ALL relaying agents are deemed willing to supply or Exceptionally, ALL relaying agents are deemed willing to supply or
accept the <dist-name> "world", and NO relaying agent should supply accept the <dist-name> "world", and NO relaying agent should supply
or accept the <dist-name> "local". 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 field and newsgroups, even when included in the Newsgroups header field and
implied (e.g. by some "wild card" notation) in the configuration implied (e.g. by some "wild card" notation) in the configuration
tables, then the agent MUST examine all group control messages (6.2) tables, then the agent MUST examine all group control messages (6.2)
in order to ensure that relaying of those messages proceeds normally. in order to ensure that relaying of those messages proceeds normally.
News Article Architecture and Protocols January 2006
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
possible distributions so that they could feed on to their possible distributions so that they could feed on to their
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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 field's content. If it matches it MUST then prepend Path header field's content. If it matches it MUST then prepend
its own <path-identity> and a '!!' <path-delimiter> to that its own <path-identity> and a '!!' <path-delimiter> to that
content. If it does not match then it prepends instead two entries content. If it does not match then it prepends instead two entries
to that content; firstly the true established <path-identity> of to that content; firstly the true established <path-identity> of
the source followed by a '!', the <path-keyword> "MISMATCH" and a the source followed by a '!', the <path-keyword> "MISMATCH" and a
further '!', and then, to the left of that, its own <path- further '!', 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
News Article Architecture and Protocols July 2005
established identities match. This header field SHOULD then be established identities match. This header field SHOULD then be
folded if it would otherwise result in a header line of excessive folded if it would otherwise result in a header line of excessive
length. length.
[This may need further changes depending on the resolution of ticket
#1047.]
[It has been suggested that relaying agents should be permitted to [It has been suggested that relaying agents should be permitted to
prepend more than the one or two entries permitted above.] prepend more than the one or two entries permitted above.]
[something like the following from Diablo might also be useful:
>>> NOTE <<< you should grep through newly created spool directories
every so often looking for .MISMATCH in the spool files to locate
incoming feeds with improperly configured I found that four of my 80+
feeds were misconfigured. ]
News Article Architecture and Protocols January 2006
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 field (or, if that is 2. It MUST examine the Injection-Date header field (or, if that is
absent, the Date header field) and reject the article as stale absent, the Date header field) and reject the article as stale
(F-3.2.1) if that predates the earliest articles of which it (F-3.2.1) if that predates the earliest articles of which it
normally keeps record, or if it is more than 24 hours into the normally keeps record, or if it is more than 24 hours into the
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7. It MAY reject any article without an Approved header field posted 7. It MAY reject any article without an Approved header field posted
to 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 field that is present. 8. It MAY delete any Xref header field that is present.
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
News Article Architecture and Protocols January 2006
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 header fields designated as variant (2.4). 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 field in o they MUST NOT create or augment a User-Agent header field in
order to identify themselves; order to identify themselves;
o they MUST NOT rewrite the Newsgroups header field in any way, o they MUST NOT rewrite the Newsgroups header field in any way,
even if some supposedly non-existent newsgroup is included; even if some supposedly non-existent newsgroup is included;
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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 IPv6 Old.site.example relayed it to a site claiming to have the IPv6
address [2001:DB8:0:0:8:800:200C:417A], and claiming (by using address [2001:DB8:0:0:8:800:200C:417A], and claiming (by using
the '!!' <path-delimiter>) to have verified that it came from the '!!' <path-delimiter>) to have verified that it came from
old.site.example. old.site.example.
News Article Architecture and Protocols July 2005
[2001:DB8:0:0:8:800:200C:417A] relayed it to "foo-server" which, [2001:DB8:0:0:8:800:200C:417A] relayed it to "foo-server" which,
not being convinced that it truly came from not being convinced that it truly came from
[2001:DB8:0:0:8:800:200C:417A], inserted the <path-keyword> [2001:DB8:0:0:8:800:200C:417A], inserted the <path-keyword>
"MISMATCH" and then did a reverse lookup on the actual source "MISMATCH" and then did a reverse lookup on the actual source
and concluded it was known as bar.isp.example (that is not to and concluded it was known as bar.isp.example (that is not to
say that [2001:DB8:0:0:8:800:200C:417A] was not a correct IPv6 say that [2001:DB8:0:0:8:800:200C:417A] was not a correct IPv6
address for bar.isp.example, but simply that that connection address for bar.isp.example, but simply that that connection
News Article Architecture and Protocols January 2006
could not be substantiated by foo-server). Observe that foo- could not be substantiated by foo-server). Observe that foo-
server has now added two entries to the Path. 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-server and barbaz decided to fold the line, It appears that foo-server and barbaz decided to fold the line,
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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 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 field as for a relaying agent article and modify the Path header field as for a relaying agent
(7.3). (7.3).
2. It MUST examine the Injection-Date header field (or, if that is 2. It MUST examine the Injection-Date header field (or, if that is
absent, the Date header field) and reject the article as stale absent, the Date header field) and reject the article as stale
(F-3.2.1) if that predates the earliest articles of which it (F-3.2.1) if that predates the earliest articles of which it
normally keeps record, or if it is more than 24 hours into the normally keeps record, or if it is more than 24 hours into the
News Article Architecture and Protocols January 2006
future (the margin MAY be 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
header fields (section F-3.1), or which contains any header field header fields (section F-3.1), or which contains any header field
that does 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).
skipping to change at page 37, line 5 skipping to change at page 35, line 53
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 or Injection-Info particular, they MUST NOT create any Injection-Date or Injection-Info
header field. 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 field should be that of the poster(s), a poster who does From header field should be that of the poster(s), a poster who does
not, for whatever reason, wish to use his own mailbox MAY use any not, for whatever reason, wish to use his own mailbox MAY use any
mailbox ending in the top level domain ".invalid" [RFC 2606]. mailbox ending in the top level domain ".invalid" [RFC 2606].
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.
News Article Architecture and Protocols January 2006
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 header involving the Newsgroups, Subject, Distribution and References header
fields. Wherever in the following it is stated that, "by default", a fields. Wherever in the following it is stated that, "by default", a
header field is to be "inherited" from one of those header fields in header field is to be "inherited" from one of those header fields in
the precursor, it means that its initial (semantic) content is to be the precursor, it means that its initial (semantic) content is to be
a copy of the content of that precursor header field. However, a copy of the content of that precursor header field. However,
skipping to change at page 38, line 5 skipping to change at page 36, line 57
7.6.1. Construction of the References header field 7.6.1. Construction of the References header field
The following procedure is to be used whenever some previous article The following procedure is to be used whenever some previous article
(the "parent") is to be referred to in the References header field (the "parent") is to be referred to in the References header field
(F-3.2.2) of a new article, whether in the course of generating a (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 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 multipart posting such as a FAQ, or the later parts of a
message/partial as suggested in [RFC 2046]). message/partial as suggested in [RFC 2046]).
News Article Architecture and Protocols July 2005
The (semantic) content of the new article's References header field The (semantic) content of the new article's References header field
consists of the content of the Message-ID header field of the parent consists of the content of the Message-ID header field of the parent
preceded, if the parent had a References header field, by the content preceded, if the parent had a References header field, by the content
of that References header field and a SP (subject to trimming as of that References header field and a SP (subject to trimming as
News Article Architecture and Protocols January 2006
described below). described below).
If the resulting References header field would, after unfolding, If the resulting References header field would, after unfolding,
exceed 998 characters in length (including its field name but not the exceed 998 characters in length (including its field name but not the
final CRLF), it MUST be trimmed (and otherwise it MAY be trimmed). final CRLF), it MUST be trimmed (and otherwise it MAY be trimmed).
Trimming involves removing any number of message identifiers from its Trimming involves removing any number of message identifiers from its
content, except that the first message identifier and the last two content, except that the first message identifier and the last two
MUST NOT be removed. MUST NOT be removed.
NOTE: There is no provision in this standard for an article to NOTE: There is no provision in this standard for an article to
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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:
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
header fields and add Comments and other informational header header fields and add Comments and other informational header
News Article Architecture and Protocols January 2006
fields). He also needs to be aware if any change he makes to the fields). He also needs to be aware if any change he makes to the
article will invalidate some authentication check provided by the article will invalidate some authentication check provided by the
poster or by 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 field contains further moderated 2. If the Newsgroups header field contains further moderated
newsgroups for which approval has not already been given, he adds newsgroups for which approval has not already been given, he adds
skipping to change at page 40, line 4 skipping to change at page 38, line 56
responsibility for having ensured that the article was approved by responsibility for having ensured that the article was approved by
the moderators of all the moderated groups involved. the moderators of all the moderated groups involved.
4. The Date header field SHOULD be retained. Any Injection-Date 4. The Date header field SHOULD be retained. Any Injection-Date
header field already present (though there should be none) MUST be header field already present (though there should be none) MUST be
removed. Exceptionally, if it is known that the injecting agent removed. Exceptionally, if it is known that the injecting agent
does not yet support the Injection-Date header field and the Date 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 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 by the moderator (e.g. delays in the moderation process) he MAY
substitute the current date. The Message-ID header field SHOULD substitute the current date. The Message-ID header field SHOULD
News Article Architecture and Protocols July 2005
also be retained unless it is obviously non-compliant with this also be retained unless it is obviously non-compliant with this
standard. standard.
News Article Architecture and Protocols January 2006
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 header fields (2.4) MUST be removed, except that a 5. Any variant header fields (2.4) MUST be removed, except that a
Path header field MAY be truncated to only those entries following Path header field MAY be truncated to only those entries following
its "POSTED" <path-keyword>. Any Injection-Info header field (F- its "POSTED" <path-keyword>. Any Injection-Info header field (F-
3.2.14) SHOULD be removed (and if not, the injecting agent will do 3.2.14) SHOULD be removed (and if not, the injecting agent will do
so, as required in 7.2.2). so, as required in 7.2.2).
skipping to change at page 41, line 4 skipping to change at page 39, line 58
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
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.
News Article Architecture and Protocols January 2006
A second general principal of gatewaying is that the transformations A second general principal of gatewaying is that the transformations
applied to the message SHOULD be as minimal as possible while still applied to the message SHOULD be as minimal as possible while still
accomplishing the gatewaying. Every change made by a gateway accomplishing the gatewaying. Every change made by a gateway
potentially breaks a property of one of the media or loses potentially breaks a property of one of the media or loses
information, and therefore only those transformations made necessary information, and therefore only those transformations made necessary
by the differences between the media should be applied. by the differences between the media should be applied.
It is worth noting that safe bidirectional gatewaying between a It is worth noting that safe bidirectional gatewaying between a
mailing list and a newsgroup is far easier if the newsgroup is mailing list and a newsgroup is far easier if the newsgroup is
moderated. Posts to the moderated group and submissions to the moderated. Posts to the moderated group and submissions to the
skipping to change at page 42, line 4 skipping to change at page 40, line 57
identifier of the other medium, but if not at least as a comment identifier of the other medium, but if not at least as a comment
in the message. This helps greatly with preventing loops. in the message. This helps greatly with preventing loops.
2. The Date 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.
News Article Architecture and Protocols January 2006
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 header fields, 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
skipping to change at page 43, line 4 skipping to change at page 41, line 58
gatewaying it, generate a corresponding cancel message of its own, gatewaying it, generate a corresponding cancel message of its own,
and inject that cancel message. and inject that cancel message.
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
News Article Architecture and Protocols January 2006
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 field in news, it SHOULD be used in the the Message-ID header field in news, it SHOULD be used in the
formation of 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
skipping to change at page 44, line 5 skipping to change at page 42, line 57
information is available, the gateway MUST supply an Injection-Date information is available, the gateway MUST supply an Injection-Date
header field with whatever date information is available, and header field with whatever date information is available, and
otherwise with the gateway's current date. If only partial otherwise with the gateway's current date. If only partial
information is available (e.g. date but not time), this SHOULD be information is available (e.g. date but not time), this SHOULD be
fleshed out to a full Date and/or Injection-Date header field by fleshed out to a full Date and/or Injection-Date header field by
adding default values rather than discarding this information. Only adding default values rather than discarding this information. Only
in very exceptional circumstances should Date information be in very exceptional circumstances should Date information be
discarded, as it plays an important role in preventing reinjection of discarded, as it plays an important role in preventing reinjection of
old messages. old messages.
News Article Architecture and Protocols July 2005
An incoming gateway MUST add a Sender header field to the news An incoming gateway MUST add a Sender header field to the news
article it forms containing the <mailbox> of the administrator of the article it forms containing the <mailbox> of the administrator of the
gateway. Problems with the gateway may be reported to this gateway. Problems with the gateway may be reported to this
News Article Architecture and Protocols January 2006
<mailbox>. The <display-name> portion of this <mailbox> SHOULD <mailbox>. The <display-name> portion of this <mailbox> SHOULD
indicate that the entity responsible for injection of the message is indicate that the entity responsible for injection of the message is
a gateway. If the original message already had a Sender header field, a gateway. If the original message already had a Sender header field,
it SHOULD be renamed so 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
skipping to change at page 45, line 5 skipping to change at page 44, line 5
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
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 News Article Architecture and Protocols January 2006
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.
See also F-5 for further security considerations related to the
format of articles.
[And a similar pointer from there to here might be in order.]
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 field (F-3.2.12) is available as a signal to "Archive: no" header field (F-3.2.12) is available as a signal to
automated archivers not to file an article, but that cannot be automated archivers not to file an article, but that cannot be
guaranteed. guaranteed.
The Distribution header field makes provision for articles which The Distribution header field makes provision for articles which
should not be propagated beyond a cooperating subnet. The key should not be propagated beyond a cooperating subnet. The key
skipping to change at page 45, line 57 skipping to change at page 45, line 5
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 January 2006
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.
News Article Architecture and Protocols July 2005
Similar effects could be caused by any email header field which could Similar effects could be caused by any email header field which could
cause every reading agent receiving it to take some externally cause every reading agent receiving it to take some externally
visible action. For example, the Disposition-Notification-To header visible action. For example, the Disposition-Notification-To header
field defined in [RFC 2298] could cause huge numbers of field defined in [RFC 2298] could cause huge numbers of
acknowledgements to be emailed to an unsuspecting third party (for acknowledgements to be emailed to an unsuspecting third party (for
which reason [RFC 2298] declares that that header field SHOULD NOT be which reason [RFC 2298] declares that that header field SHOULD NOT be
used in Netnews). 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
skipping to change at page 46, line 55 skipping to change at page 46, line 5
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-3.2.14) the network by making proper use of the Injection-Info (F-3.2.14)
header field, it makes no provision for enforcement, which may in header field, it makes no provision for enforcement, which may in
consequence be patchy. Nevertheless, injecting sites which consequence be patchy. Nevertheless, injecting sites which
persistently fail to honour their responsibilities or to comply with persistently fail to honour their responsibilities or to comply with
generally accepted standards of behaviour are likely to find generally accepted standards of behaviour are likely to find
themselves blacklisted, with their articles refused propagation and themselves blacklisted, with their articles refused propagation and
even subject to cancellation, and other relaying sites would be well even subject to cancellation, and other relaying sites would be well
advised to withdraw peering arrangements from them. advised to withdraw peering arrangements from them.
News Article Architecture and Protocols January 2006
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 field) or by checking inspection (particularly of the Approved header field) or by checking
any digital signatures that may be provided (see 6.1). In addition, any digital signatures that may be provided (see 6.1). In addition,
they 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
skipping to change at page 47, line 51 skipping to change at page 46, line 57
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
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. News Article Architecture and Protocols January 2006
News Article Architecture and Protocols July 2005 reading agent has terminated.
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 field that may be present. contrary to any Archive header field that may be present.
skipping to change at page 48, line 56 skipping to change at page 48, line 5
the obsoleted "message/news". the obsoleted "message/news".
10. References 10. References
10.1. Normative References 10.1. Normative References
[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.
News Article Architecture and Protocols January 2006
[RFC 2048] N. Freed, J. Klensin, and J. Postel, "Multipurpose [RFC 2048] N. Freed, J. Klensin, and J. Postel, "Multipurpose
Internet Mail Extensions (MIME) Part Four: Registration Internet Mail Extensions (MIME) Part Four: Registration
Procedures", RFC 2048, November 1996. Procedures", RFC 2048, November 1996.
News Article Architecture and Protocols July 2005
[RFC 2119] S. Bradner, "Key words for use in RFCs to Indicate [RFC 2119] S. Bradner, "Key words for use in RFCs to Indicate
Requirement Levels", RFC 2119, March 1997. Requirement Levels", RFC 2119, March 1997.
[RFC 2606] D. Eastlake and A. Panitz, "Reserved Top Level DNS Names", [RFC 2606] D. Eastlake and A. Panitz, "Reserved Top Level DNS Names",
RFC 2606, June 1999. RFC 2606, June 1999.
[RFC 2822] P. Resnick, "Internet Message Format", RFC 2822, April [RFC 2822] P. Resnick, "Internet Message Format", RFC 2822, April
2001. 2001.
[RFC 3864] G. Klyne, M. Nottingham, and J. Mogul, "Registration [RFC 3864] G. Klyne, M. Nottingham, and J. Mogul, "Registration
skipping to change at page 49, line 28 skipping to change at page 48, line 32
[USEAGE] draft-ietf-usefor-useage-*.txt. [USEAGE] draft-ietf-usefor-useage-*.txt.
[USEFOR] K. Murchison et al, "News Article Format", draft-ietf- [USEFOR] K. Murchison et al, "News Article Format", draft-ietf-
usefor-usefor-*.txt. usefor-usefor-*.txt.
[USEPRO] This Standard. [USEPRO] This Standard.
10.2. Informative References 10.2. Informative References
[ARTICLE] Charles H. Lindsey, "News Article Format and Transmission",
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 2046] N. Freed and N. Borenstein, "Multipurpose Internet Mail [RFC 2046] N. Freed and N. Borenstein, "Multipurpose Internet Mail
Extensions (MIME) Part Two: Media Types", RFC 2046, November Extensions (MIME) Part Two: Media Types", RFC 2046, November
1996. 1996.
[RFC 2142] D. Crocker, "Mailbox Names for Common Services, Roles and [RFC 2142] D. Crocker, "Mailbox Names for Common Services, Roles and
Functions", RFC 2142, May 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 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 3986] T. Berners-Lee, R. Fielding, and L. Masinter, "Uniform News Article Architecture and Protocols January 2006
Resource Identifier (URI): Generic Syntax", STD 66, January
2005.
[RFC 850] Mark R. Horton, "Standard for interchange of Usenet [RFC 2821] John C. Klensin and Dawn P. Mann, "Simple Mail Transfer
messages", RFC 850, June 1983. Protocol", RFC 2821, April 2001.
[RFC 976] Mark R. Horton, "UUCP mail interchange format standard", [RFC 976] Mark R. Horton, "UUCP mail interchange format standard",
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.
11. Acknowledgements 11. Acknowledgements
TBD As this document is the result of an eight year effort, the number of
people that have contributed to its content are too numerous to
mention individually. Many thanks go out to all past and present
members of the USEFOR Working Group of the Internet Engineering Task
Force (IETF) and the accompanying mailing list.
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@clerew.man.ac.uk
[ [
Working group chairs Working group chairs
Alexey Melnikov <alexey.melnikov-usefor@isode.com> Alexey Melnikov <alexey.melnikov-usefor@isode.com>
Harald Tveit Alvestrand <harald@alvestrand.no> 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 - Obsolete Control Messages
The obsolete "A News" article format consisted of exactly five lines
of header field information, followed by the body. For example:
News Article Architecture and Protocols July 2005
Aeagle.642
news.misc
cbosgd!mhuxj!mhuxt!eagle!jerry
Fri Nov 19 16:14:55 1982
Usenet Etiquette - Please Read
body
body
body
The first line consisted of an "A" followed by an article ID
(analogous to a message identifier and used for similar purposes).
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
width), resembling an Internet date but not quite the same. The fifth
was the subject.
This format is documented for archaeological purposes only. Articles
MUST NOT be generated in this format.
Appendix A.2 - Early B-News Article Format
The obsolete pseudo-Internet article format, used briefly during the
transition between the A News format and the modern format, followed
the general outline of a MAIL message but with some non-standard
header fields. For example:
From: cbosgd!mhuxj!mhuxt!eagle!jerry (Jerry Schwarz)
Newsgroups: news.misc
Title: Usenet Etiquette -- Please Read
Article-I.D.: eagle.642
Posted: Fri Nov 19 16:14:55 1982
Received: Fri Nov 19 16:59:30 1982
Expires: Mon Jan 1 00:00:00 1990
body
body
body
The From header field contained the information now found in the Path
header field, plus possibly the full name now typically found in the
From header field. The Title header field contained what is now the
content of the Subject header field. The Posted header field
contained what is now the content of the Date header field. The
Article-I.D. header field contained an article ID, analogous to a
message identifier and used for similar purposes. The Newsgroups and
Expires header fields were approximately as now. The Received header
field contained the date when the latest relaying agent to process
the article first saw it. All dates were in the above format, with
all fields fixed width, resembling an Internet date but not quite the
same.
This format is documented for archaeological purposes only. Articles
MUST NOT be generated in this format.
News Article Architecture and Protocols July 2005
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
information about their internal connectivity to be confidential. information about their internal connectivity to be confidential.
News Article Architecture and Protocols January 2006
version version
sendsys sendsys
whogets whogets
senduuname senduuname
"Version" requested details of the transport software in use at a "Version" requested details of the transport software in use at a
site. "Sendsys" requested the full list of newsgroups taken, and the site. "Sendsys" requested the full list of newsgroups taken, and the
peering arrangements. "Whogets" was similar, but restricted to a peering arrangements. "Whogets" 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.
skipping to change at page 53, line 5 skipping to change at page 50, line 51
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 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.
News Article Architecture and Protocols January 2006
Full Copyright Statement Full Copyright Statement
Copyright (C) The Internet Society (2005). This document is subject Copyright (C) The Internet Society (2006). This document is subject
to the rights, licenses and restrictions contained in BCP 78, and to the rights, licenses and restrictions contained in BCP 78, and
except as set forth therein, the authors retain all their rights. except as set forth therein, the authors retain all their rights.
This document and the information contained herein are provided on an This document and the information contained herein are provided on an
"AS IS" basis and THE CONTRIBUTOR, THE ORGANIZATION HE/SHE REPRESENTS "AS IS" basis and THE CONTRIBUTOR, THE ORGANIZATION HE/SHE REPRESENTS
OR IS SPONSORED BY (IF ANY), THE INTERNET SOCIETY AND THE INTERNET OR IS SPONSORED BY (IF ANY), THE INTERNET SOCIETY AND THE INTERNET
ENGINEERING TASK FORCE DISCLAIM ALL WARRANTIES, EXPRESS OR IMPLIED, ENGINEERING TASK FORCE DISCLAIM ALL WARRANTIES, EXPRESS OR IMPLIED,
INCLUDING BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE INCLUDING BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE
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.
skipping to change at page 54, line 5 skipping to change at page 51, line 54
7.3 Step 4. 7.3 Step 4.
4 Part of the procedure for examining Path header fields by 4 Part of the procedure for examining Path header fields by
relaying agents has been moved to serving agents, as explained relaying agents has been moved to serving agents, as explained
in 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 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].]
News Article Architecture and Protocols January 2006
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
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
skipping to change at page 55, line 5 skipping to change at page 52, line 53
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 July 2005
2 Consequent changes to "variant header field", and also mention 2 Consequent changes to "variant header field", and also mention
of 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.
News Article Architecture and Protocols January 2006
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
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7 New section on Identification of news-servers describing 7 New section on Identification of news-servers describing
acceptable forms for <path-identity>s. acceptable forms for <path-identity>s.
2.3 2.3
8 Definition of "semantic content" of a header field. 8 Definition of "semantic content" of a header field.
2.1 2.1
9 Systematic replacement of "header" by "header field". 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 10 More stringent rules for checking <newsgroup-name>s in control
messages for compliance with USEFOR. messages for compliance with USEFOR.
6.2 6.2
For version 05
News Article Architecture and Protocols January 2006
1 Historical Appendices A.1 and A.2 removed, in anticipation of
republication of Son-of-1036 as an Informational RFC.
1.3
2 Definitions of technical terms adopted from USEFOR rather than
defining them separately.
3 Discussion of <path-identity> rewritten to reflect recent
developments (but still awaiting further work in USEFOR).
2.3
4 Items now included in Appendix A of USEFOR have been removed
from section 3, and the "Transitional Arrangements" (which still
cover the USEFOR changes) have been modified to reflect this.
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