s-o-1036 June 1994

4.2.2. Undesirable Headers

A header whose content is empty  is  said  to  be  an  empty
header.   Relayers  and  reading  agents SHOULD not consider
presence or absence of an empty header to alter  the  seman-
tics  of  an  article  (although  syntactic  rules,  such as
requirements that certain header names appear at  most  once
in  an  article,  MUST  still be satisfied).  Posting agents
SHOULD delete empty headers  from  articles  before  posting
them.

INTERNET DRAFT to be        NEWS                  sec. 4.2.2


Headers  that merely state defaults explicitly (e.g., a Fol-
lowup-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,  con-
veying no information whatsoever.  Headers that state infor-
mation which cannot possibly be of use to a significant num-
ber  of relayers, reading agents, or readers (e.g., the name
of the software package used as the posting agent) are  use-
less and pointless.  Posters and posting agents SHOULD avoid
including redundant or useless headers in articles.

     NOTE: Information that someone,  somewhere,  might
     someday  find useful is best omitted from headers.
     (There's quite enough of it  in  article  bodies.)
     Headers  should contain information of known util-
     ity only.  This is not meant to preclude inclusion
     of  information  primarily meant for news-software
     debugging, but such information should be included
     only  if there is real reason, preferably based on
     experience, to suspect that it  may  be  genuinely
     useful.  Articles passing through gateways are the
     only obvious case  where  inclusion  of  debugging
     information appears clearly legitimate.  (See sec-
     tion 10.1.)

     NOTE: A useful rule of thumb for  software  imple-
     mentors  is:  "if  I had to pay a dollar a day for
     the transmission of this  header,  would  I  still
     think it worthwhile?".