Interesting problem. This hasn't been addressed yet, so it might be something worth looking into. The only thing is, as you know, most people here use No-Intro in their cabinets and may keep a GoodSet for archival (because they want it all!). Anyway, if you want a solution to your problem that doesn't require Tom's help, I would suggest a script. I was thinking this script would need to step through your set(s), extract all files to a temp directory, delete files that don't match your criteria (if USA available, delete JAP, EUR, etc), rezip the files to a new set location, move on... This isn't too challenging, but it would be nice if you didn't have to do it. A map file or an edited database would do the same thing by only displaying games that matched, but it might be more work. The real problem is figuring out what files you want/don't want in an algorithmic way.