News and mail messages consist of headers, a completely blank line,
and the body.  For a followup message you usually won't need to edit
the headers at all.  When you start a thread, usually the only
headers you'll need to think about are the Newsgroups and Subject
headers.  Sometimes you may want to edit other headers.  The next
sections describe the Newsgroups, Followup-To, Subject, and
References headers.

For some general information about headers, see the "Customized
Headers" section of the "Signature, Finger, and Customized Headers
FAQ" which is regularly posted to news.software.nn and archived in
all the usual FAQ archives including:

http://www.cis.ohio-state.edu/hypertext/faq/usenet/signature_finger_faq/faq.html
ftp://rtfm.mit.edu/pub/usenet/news.answers/signature_finger_faq

Some parts © 2009 Advameg, Inc.