Yeah, if category information is what you want, catver.ini is how you get it. You need to download the version for your version of MAME and tell MAMEWAH where it is in the emulator config, then re-generate your default list.
Do a search for ListGen. If you want to do anything complex or fancy, it's definitely the tool to use.
If you want to just do basic stuff, like filter out all the games of a particular type or year for example, MAMEWAH can do that all by itself. Make a favorites list and play around with MAMEWAH's menus and you'll find the filter options.
If you want to do basic stuff but in a decent GUI that will let you use the mouse and pick and choose your games, check out MAMEWAH Config.
-sab