In article , ?B?bW9uaXI=?= wrote:
joeu2004;

Generally I don't make distinction between discussion groups, forums, news
group, Google groups, usenets, etc. I refer to them collectively as
discussion groups (or DGs).
I'm sure each was designed, and is monitored, controlled and (possibly)
moderated differently.

You may not make such a distinction, but it certainly exists. :)
News groups are quite a different beast to forums. Knowing how they work
might help you to work out the easiest way to do what you want ? :)

My inquiry is really a simple one. Whoever developed and is in-charge of
the OnLine MS Communities should at least explain what s/he means by "use the
full USENET designation" under "Advanced Options", provides a sample address,
and clearly states if the option applies ONLY to MS Communities.

News groups are many and varied. The MS groups have some kind of connection
to "real" newsgroups ... I suspect by design. I suspect that items posted
from MS groups show in the "from" feild something like this :::
?Utf-8?B?bW9uaXI=?= <actual user

That said, I admit I don't really understand it, as real news groups work
fine for me. :)

I'm inclined to follow your earlier suggestion of picking just one (this
one) and forget about cross-posting all together!

An excellent inclination. Go with it. :) :)