usefor-article-13 May 2004

4.2.5.3.  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 some 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 principal 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 reading agents serviced by a
       particular serving agent can mark such articles as read.

--- ../usefor-article-12/Variant_Headers.out          November 2003
+++ ../usefor-article-13/Variant_Headers.out          May 2004