The message
from (Spud Demon) contains these words:

Janet Baraclough writes in article
dated Thu, 14 Jul 2005
16:39:24 +0100:
You are not in a forum. You are posting to an international, but
mostly American newsgroup.

Is there something about this newsgroup that makes it not a forum?

The OP is posting from a UK commercial website (www.gardenbanter)
which provides a portal to usenet newsgroups. Unfortunately, the website
does not really explain that to its members, so they mistakenly think
they are posting to a forum belonging to and operated by the website.
This appears to suit the webmaster's intentions.

There are significant differences, from a users POV, between a
website forum, and this newsgroup. Website forums are controlled by the
webmaster, often, to please, or at least avoid offending, the intersts
of advertisers who buy space there. So, gardenbanter moderates the
content of this newsgroup as it appears on their so-called "forum". Its
members are reading this newsgroup in a bowdlerised version moderated
for content and language.

Another difference is that on a website forum the webmaster/website
technology dictates how long messages and threads stay on view to users.
Many busy website forums/message boards are almost as transient as a
chatroom, and there's nothing the user can do about that. In
gardenbanter's case, this has the unwelcome effect of giving its members
a very short attention span. They can't keep an interesting thread in
full view as long as they choose, and therefore often have the greatest
difficulty in following threads and contributing to complex
conversations.

Mostly, though not in this case, gardenbanters UK members manage to
hit the "forum" which leads them to uk.rec.gardening where they can get
UK-relevant advice. In that newsgroup, they have inadvertently caused
much thread disruption partly due to poor technology at the website
which forwards their posts...starting a new thread for each post, for
example, and not using reply-with-quote. They would be far better off,
imho, using any other method to read and post to newsgroups.

HTH

Janet.