usefor-article-13 May 2004

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).

--- ../usefor-article-12/Newsgroups.out          November 2003
+++ ../usefor-article-13/Newsgroups.out          May 2004
@@ -37,8 +37,6 @@
    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.