usefor-article-09 February 2003

4.2.6.  Undesirable Headers

   A header whose content is empty is said to be an empty header (in
   fact, no such headers are defined by this standard).  Relaying and
   reading agents SHOULD NOT consider presence or absence of an empty
   header to alter the semantics of an article (although syntactic
   rules, such as requirements that certain header-names appear at most
   once, MUST still be satisfied). Posting and injecting agents SHOULD
   delete empty headers from articles before posting them; relaying
   agents MUST pass them untouched.

   Headers that merely state defaults explicitly (e.g., a Followup-To-
   header with the same content as the Newsgroups-header, or a MIME
   Content-Type-header with contents "text/plain; charset=us-ascii") or
   state information that reading agents can typically determine easily
   themselves (e.g. the length of the body in octets) are redundant and
   posters and posting agents Ought Not to include them.

--- ../usefor-article-08/Undesirable_Headers.out          August 2002
+++ ../usefor-article-09/Undesirable_Headers.out          February 2003