1) This data is stored in the data.mdb file for MAME games. For other games, you can edit the system specific database file that you point to. You will need to reboot GameEx to see the changes take effect. Be aware that if you update your MAME list, you will lose all changes that you made to your MAME info. The only way around this is to update the input files (history.txt etc) rather than the compiled file (data.mdb). 2) You can edit this info for non-MAME stuff in the database file. For MAME, you can edit your catver.ini file. I created a script that helps rename the categories as you wish. If interested, you can search for my post or ask and I'll find it. You cannot add more filter criteria, but you can change the data that's available to sort on. 3) I don't think you can sort by system in the 'All Games' list AFAIK. Hope that helps!