usefor-article-13 May 2004

8.4.  Duties of a Serving Agent

   A Serving Agent takes an article from a relaying or injecting agent
   and files it in a "news database". It also provides an interface for
   reading agents to access the news database. This database is normally
   indexed by newsgroup with articles in each newsgroup identified by an
   article-locator (usually in the form of a decimal number - see 6.16).

        NOTE: Since control messages are often of interest, but should
        not be displayed as normal articles in regular newsgroups, it is
        common for serving agents to make them available in a pseudo-
        newsgroup named "control" or in a pseudo-newsgroup in a sub-
        hierarchy under "control." (e.g. "control.cancel").

   A serving agent processes articles as follows:

   1. It MUST verify the leftmost entry in the Path-header and then
      prepend its own path-identity with a '/' path-delimiter, and
      possibly also the verified path-identity of its source with a '?'
      path-delimiter (5.6.2).

   2. It MUST examine the Injection-Date-header (or, if that is absent,
      the Date-header) and reject the article as stale (5.7) if that
      predates the earliest articles of which it normally keeps record,
      or if it is more than 24 hours into the future (the margin MAY be
      less than that 24 hours).

   3. It MUST reject any article that does not have the correct
      mandatory headers (section 5) present, or which contains any
      header that does not have legal contents.


   4. It SHOULD reject any article that has already been sent to it (a
      database of message identifiers of recent messages is usually kept
      and matched against).

   5. It SHOULD reject any article that matches an already received
      cancel message (or an equivalent Supersedes-header) issued by its
      poster or by some other trusted entity.

   6. It MUST reject any article without an Approved-header posted to
      any moderated newsgroup which it is configured to receive, and it
      MAY reject such articles for any newsgroup it knows to be
      moderated.

   7. It MUST remove any Xref-header (6.16) from each article.  It then
      MAY (and usually will) generate a fresh Xref-header.

   8. Finally, it stores the article in its news database.

--- ../usefor-article-12/Duties_of_a_Serving_Agent.out          November 2003
+++ ../usefor-article-13/Duties_of_a_Serving_Agent.out          May 2004
@@ -19,11 +19,16 @@
       possibly also the verified path-identity of its source with a '?'
       path-delimiter (5.6.2).
 
-   2. It MUST reject any article whose Date-header is stale (see 5.1).
+   2. It MUST examine the Injection-Date-header (or, if that is absent,
+      the Date-header) and reject the article as stale (5.7) if that
+      predates the earliest articles of which it normally keeps record,
+      or if it is more than 24 hours into the future (the margin MAY be
+      less than that 24 hours).
 
    3. It MUST reject any article that does not have the correct
       mandatory headers (section 5) present, or which contains any
       header that does not have legal contents.
+
 
    4. It SHOULD reject any article that has already been sent to it (a
       database of message identifiers of recent messages is usually kept