I think I would need an overall description of the forum features -- something along the lines:
- The forum essentially manages a set of topics. Those are discussions (sometimes also called threads) consisting of a top post and its replies presented in a reply hierarchy. Top post and replies together are called "post"s.
- Each topic has an associated "category" used to group related topics together.
- Each user has a "user page" he can customize via his preferences. Among others he can see there an overview of his watched or tracked categories (side note: I have not understood the exact difference between "watching" and "tracking"), get of overview of his (forum) notifications, his posts, etc.
- A user can reply to a specific topic, a specific reply or send a private reply to the author (I have not yet seen how to do the last operation).
- The forum can inform a user (controlled via his preferences) via email about important events: e.g. new posts, replies to his posts, reference to him via "@" in other posts (these features seems to not yet work reliably - or I do not yet fully understand how they should work).