usefor-article-11 June 2003

6.6.  Distribution

   The Distribution-header is an inheritable header (see 4.2.5.2) which
   specifies geographical or organizational limits to an article's
   propagation.

      header              =/ Distribution-header
      Distribution-header = "Distribution" ":" SP Distribution-content
                     *( ";" extension-parameter )
      Distribution-content= distribution *( dist-delim distribution )
      dist-delim          = ","
      distribution        = [FWS] distribution-name [FWS]
      distribution-name   = ALPHA 1*distribution-rest
      distribution-rest   = ALPHA / "+" / "-" / "_"

   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 distributions in the
   Distribution-header.  Additionally, reading agents MAY also be
   configured so that unwanted distributions do not get displayed.

        NOTE: Although it would seem redundant to filter out unwanted
        distributions at both ends of a relaying link (and it is clearly
        more efficient to do so at the sending end), many sending sites
        have been reluctant, historically speaking, to apply such
        filters (except to ensure that distributions local to their own
        site or cooperating subnet did not escape); moreover they tended
        to configure their filters on an "all but those listed" basis,
        so that new and hitherto unheard of distributions would not be
        caught. Indeed many "hub" sites actually wanted to receive all
        possible distributions so that they could feed on to their
        clients in all possible geographical (or organizational)
        regions.

        Therefore, it is desirable to provide facilities for rejecting
        unwanted distributions at the receiving end. Indeed, it may be
        simpler to do so locally than to inform each sending site of
        what is required, especially in the case of specialized
        distributions (for example for control messages, such as cancels
        from certain issuers) which might need to be added at short
        notice.  The possibility for reading agents to filter
        distributions has been provided for the same reason.

   Exceptionally, ALL relaying agents are deemed willing to supply or
   accept the distribution "world", and NO relaying agent should supply
   or accept the distribution "local".  However, "world" SHOULD NEVER be
   mentioned explicitly since it is the default when the Distribution-
   header is absent entirely.  "All" MUST NOT be used as a
   distribution-name.  Distribution-names SHOULD contain at least three
   characters, except when they are two-letter country names as in [ISO
   3166].  Distribution-names are case-insensitive (i.e. "US", "Us" and
   "us" all specify the same distribution).

   Followup agents SHOULD initially supply the same Distribution-header
   as found in the precursor.

--- ../usefor-article-10/Distribution.out          April 2003
+++ ../usefor-article-11/Distribution.out          June 2003
@@ -51,8 +51,6 @@
    3166].  Distribution-names are case-insensitive (i.e. "US", "Us" and
    "us" all specify the same distribution).
 
-   Posting agents Ought Not to provide a default Distribution-header
-   without giving the poster an opportunity to override it. Followup
-   agents SHOULD initially supply the same Distribution-header as found
-   in the precursor.
+   Followup agents SHOULD initially supply the same Distribution-header
+   as found in the precursor.