Good question :) Crossposting is the practice of adding unrelated or an
excessive number of newsgroups  to a message in an attempt to reach more
readers. The result is unnecessary traffic on the server and duplication of
not only the question but every reply. Posts with more than two included
groups are ignored by many people. There are lots of sources of info on
"netiquette" on the web, such as
www.cis.ohio-state.edu/hypertext/faq/usenet/finding-groups/general/faq.html
It may seem silly to some people at first, (i.e. THIS IS SHOUTING) but take
my word for it, if you want to stay out of people's bad graces, take a
little look at this stuff.
..visit Bill Whipple at microsoft.public.netiquette.
--
Lee
MS-MVP (DTS)