Hi Skorpion,
thanx for asking me.
UBB has three hierarchies:
1. Categories
2. Boards
3. Topics
(Ok, you can say that there is also a fourth one: one topic with all replies. But here in my consideration it doesn't count)
So maybe I can make this clear with an example:
Look at the German Board in UBB Developers Network. Once selected you are directly in the Boards-Hierarchy. But it would be better if it has been splitted up in several categories. E.g. "Design Integration", "Templates", "Mod Questions", etc. (of course the german words for this

)
This means: you have at the top level categories, from here you can select your needed board, and in your board you also may select from several categories.
I'm not good in explaining (especially in english). So let me express my needs in an example where I pinpoint the hierarchies:
Categories Boards (Categories) Topics
------------------------------------------------------------------
Announcements Announcement - Team UBBDev
Join Team
...
Modifications Mod Ideas - User selects
Moderator Log
vBulletin
...
Intern. Supp. German Forum (Design Integration) Einbau von Graemlins
Header-Footer Problem
...
(Templates) ...
(Mod Questions) Newsfader Beta
...
...
...
...
(Categories) would be the new hierarchy. The belonging entries are listet also in brackets.
I appreciate your help. Thanx a lot.
Jochen