The most common way to use a Forum is the the way that @Adam Clark just described: The mentioning of the forum via the exclamation mark from your account. Does this work with your forum?

Concerning the posting to a Forum directly on the Forum's profile: You did this with this posting, so it does work in general. But to make this work, you have to visit the remote site via a "magic link" (this /redir stuff). I guess the same is valid when the forum is on the same machine like your user account.

Ahaa... ok, this is something I did not know. I have never seen a forum where you have to mention it in a general post with a special character. I am used to forums where you go to the forum's page, and then there's a "start new topic" link or button or blank form or something which lets you post there.

The only way I knew how to post in this support forum is because the "new post" icon appears at the top of the sreen.

But unfortunately I do not see this "new post" button on my own forum, so I do not know how to post in it. Is there any way I can force it to appear? How do I do the "magic link" thing?

I think #FacebookRefugees like myself are expecting the forum page to have a button or box/form to fill in, because that's how we post to groups or other people's walls. I don't think we would intuitively realise that we have to use special characters in general posts. On FB that would just be a way of tagging someone, but not a way of posting on their walls.