Forum mentions
 

Is it possible to mention someone in a forum post so mentioned person gets notification?

Nope, not afaik.
You can quote them but it's just a quote without a notification.
If ppl are the owner of the addon they can see that someone posted a comment via the "Author" forum menu.
Al others can use the "Subscribe to thread" function to get notified as a new comment/post arrives. (via email e.g.)