Hi, with regards to catver.ini: place it in the MAME directory (where the executable is)
Purpose is to categorize each game, e.g. like this
av2mj1bb = Tabletop / Mahjong * Mature *
So it's easy for you to e.g. filter out all the "Mahjong" games which anyhow nearly nobody plays ;-)
Furthermore a quote from raygun:
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in the emulator configuration, one of the fields is called 'additional import files' or something like that. Put the full path to your catver.ini file in there and then regenerate your romlist. That should pick up the categories.
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http://forum.attractmode.org/index.php?topic=24.msg91#msg91