In article ,
"Rick Brandt" wrote:

As long as you keep the list of groups to three (maybe four)
or less and all the groups are relevant then crossposting
is fine and MUCH preferred to Multi-Posting.

Agreed.

My newsreader will mark as READ an article that I have already read in one
group but is crossposted to another group I read. (No point in reading the
same article twice. That is where the annoyance factor comes in.)

Posting the same article individually to each of several groups circumvents
the above feature/aid. That is when the annoyance factor REALLY soars.

On those rare occasions when I crosspost an article, I try to include
"[Crossposted]" in the first line of the body. I consider this a courtesy to
those that might reply but do NOT want their newsreader to automatically
crosspost their reply. (This alerts the replier(?) that they may wish to edit
OUT the additional newsgroups before posting.)
--

JR