usefor-article-12 November 2003
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5.5. Newsgroups
The Newsgroups-header's content specifies the newsgroup(s) in which
the article is intended to appear. It is an inheritable header
(4.2.5.2) which then becomes the default Newsgroups-header of any
followup, unless a Followup-To-header is present to prescribe
otherwise (see 8.6). Articles MUST NOT be passed between relaying
agents or to serving agents unless the sending agent has been
configured to supply and the receiving agent to receive at least one
of the newsgroup-names in the Newsgroups-header.
header =/ Newsgroups-header
Newsgroups-header = "Newsgroups" ":" SP Newsgroups-content
*( ";" extension-parameter )
Newsgroups-content = [FWS] newsgroup-name
*( [FWS] ng-delim [FWS] newsgroup-name )
[FWS]
newsgroup-name = component *( "." component )
component = 1*component-grapheme
ng-delim = ","
component-grapheme = DIGIT / ALPHA / "+" / "-" / "_"
[Maybe some better word for 'grapheme'.]
NOTE: Observe that the syntax does not allow comments within the
Newsgroups-header; this is to simplify processing by relaying
and serving agents which have a requirement to process this
header extremely rapidly.
Components beginning with underline ("_") are reserved for use by
future versions of this standard and MUST NOT occur in newsgroup-
names (whether in Newsgroups-headers or in newgroup control messages
(7.2.1)). However, such names MUST be accepted.
Components beginning with "+" or "-" are reserved for use by
implementations and MUST NOT occur in newsgroup-names (whether in
Newsgroups-headers or in newgroup control messages). Implementors may
assume that this rule will not change in any future version of this
standard.
NOTE: For example, implementors may safely use leading "+" and
"-" to "escape" other entities within something that looks like
a newsgroup-name.
The format of newsgroup-names is ultimately determined by the
policies of those administrative agencies which have the
responsibility for creating new newsgroups within the various
hierarchies of Usenet. There are traditional, social and technical
arguments why there should be restrictions on these formats (and the
force of the technical ones changes over time with developments in
computers and operating systems). Therefore, such administrative
agencies SHOULD establish and promulgate the restrictions they intend
to apply within their own hierarchies.
NOTE: These issues are discussed more fully in [USEAGE]. The
following policy restrictions represent what is considered safe
and appropriate at the present time. Although purely advisory,
hierarchy administrators should consider the consequences
carefully before allowing them to be exceeded. They could also
be taken as the defaults in unmanaged hierarchies.
1. Uppercase letters are forbidden.
2. A component name is forbidden to consist entirely of digits.
3. A component is limited to 30 component-graphemes and a
newsgroup-name to 66 component-graphemes (counting also the
'.'s separating the components).
Serving and relaying agents MUST accept any syntactially correct
newsgroup-name even if it would violate whatever policy restrictions
may be in place. Posting and injecting agents MAY enforce them (but
only with the explicit agreement of the poster).
The inclusion of folding white space within a Newsgroups-content is a
newly introduced feature in this standard. It MUST be accepted by all
conforming implementations (relaying agents, serving agents and
reading agents). Posting agents should be aware that such postings
may be rejected by overly-critical old-style relaying agents. When a
sufficient number of relaying agents are in conformance, posting
agents SHOULD generate such whitespace in the form of <CRLF WSP> so
as to keep the length of lines in the relevant headers (notably
Newsgroups and Followup-To) to a reasonable length (such as 79
characters, which is likely to be displayed satisfactorily by most
current reading agents). Before such critical mass occurs, injecting
agents MAY reformat such headers by removing whitespace inserted by
the posting agent, but relaying agents MUST NOT do so.
Posters SHOULD use only the names of existing newsgroups in the
Newsgroups-header. However, it is legitimate to cross-post to
newsgroups which do not exist on the posting agent's host, provided
that at least one of the newsgroups DOES exist there. Relaying agents
MUST NOT rewrite Newsgroups-headers in any way, even if some or all
of the newsgroups do not exist on the relaying agent's host. Serving
agents MUST NOT create new newsgroups simply because an unrecognized
newsgroup-name occurs in a Newsgroups-header (see 7.2.1 for the
correct method of newsgroup creation).
The Newsgroups-header is intended for use in Netnews articles rather
than in email messages. It MAY be used in an email message to
indicate that it is a copy also posted to the listed newsgroups, in
which case the inclusion of a Posted-And-Mailed header (6.9) would
also be appropriate. However, it SHOULD NOT be used in an email-only
reply to a Netnews article (thus the "inheritable" property of this
header applies only to followups to a newsgroup, and not to followups
to the poster).
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#Diff to first older
--- ../usefor-article-11/Newsgroups.out June 2003
+++ ../usefor-article-12/Newsgroups.out November 2003
@@ -19,8 +19,6 @@
component = 1*component-grapheme
ng-delim = ","
component-grapheme = DIGIT / ALPHA / "+" / "-" / "_"
-
-
[Maybe some better word for 'grapheme'.]
NOTE: Observe that the syntax does not allow comments within the
@@ -39,6 +37,8 @@
assume that this rule will not change in any future version of this
standard.
+
+
NOTE: For example, implementors may safely use leading "+" and
"-" to "escape" other entities within something that looks like
a newsgroup-name.
@@ -49,7 +49,7 @@
hierarchies of Usenet. There are traditional, social and technical
arguments why there should be restrictions on these formats (and the
force of the technical ones changes over time with developments in
- computers and operating systems) Therefore, such administrative
+ computers and operating systems). Therefore, such administrative
agencies SHOULD establish and promulgate the restrictions they intend
to apply within their own hierarchies.
@@ -65,11 +65,8 @@
2. A component name is forbidden to consist entirely of digits.
3. A component is limited to 30 component-graphemes and a
- newsgroup-name to 71 component-graphemes (counting also the
+ newsgroup-name to 66 component-graphemes (counting also the
'.'s separating the components).
-[There was a suggestion to reduce that 71 to 66 in order to allow such a
-newsgoup-name to fit in the on the first line of a Followup-To-header
-without exceeding 79 characters.]
Serving and relaying agents MUST accept any syntactially correct
newsgroup-name even if it would violate whatever policy restrictions