INTERNET-DRAFT                               Charles H. Lindsey
Usenet Format Working Group                  University of Manchester
                                             July 2001

4.2.2.3. Variant Headers

4.2.2.3.  Variant Headers
   Headers with the variant property may differ between (or even be
   completely absent from) copies of the same article as stored or
   relayed throughout a Netnews system. The manner of the difference (or
   absence) MUST be as specified in this (or any future) standard.
   Typically, these headers are modified as articles are propagated, or
   they reflect the status of the article on a particular serving agent,
   or cooperating group of such agents. The variant header MAY be placed
   anywhere within the headers (though placing it first is recommended).
   The principle examples are:
     o Path (5.6) - augmented at each relaying agent that an article
       passes through.
     o Xref (6.16) - used to keep track of the article locators of
       crossposted articles so that newsreaders serviced by a particular
       serving agent can mark such articles as read.

Diffs to previous draft

--- {draft-04}	Wed Jul 11 21:55:09 2001
+++ {draft-05}	Wed Jul 11 21:55:10 2001
@@ -1,8 +1,16 @@
-
4.2.2.4.  Variant Headers
-   Headers with the variant property are modified as articles are
-   propagated. The modified header MAY be placed anywhere within the
-   headers (though placing it first is recommended). The principle
-   example is:
+
4.2.2.3.  Variant Headers
+   Headers with the variant property may differ between (or even be
+   completely absent from) copies of the same article as stored or
+   relayed throughout a Netnews system. The manner of the difference (or
+   absence) MUST be as specified in this (or any future) standard.
+   Typically, these headers are modified as articles are propagated, or
+   they reflect the status of the article on a particular serving agent,
+   or cooperating group of such agents. The variant header MAY be placed
+   anywhere within the headers (though placing it first is recommended).
+   The principle examples are:
      o Path (5.6) - augmented at each relaying agent that an article
        passes through.
+     o Xref (6.16) - used to keep track of the article locators of
+       crossposted articles so that newsreaders serviced by a particular
+       serving agent can mark such articles as read.