I have wondering why there is so many different extensions on the .nes file ??? I have figured out that (U) Is USA (E) Is Europe (J) Is Japan (UNL) Is Unlicenced. (UE), (UEJ), (JU), (EJ) (Maybe the same rom for all regions?) But i cant figure these out: [a1], [a2].. (does this stand for alternate or alternative?) [!] (Maybe a bad rom?) (I have no idea regarding this one.. (PRG 0), (PRG1).. (no idea..) (REV A), (REV B).. (no idea..) (VS) (no idea..) [h1], [h2] (Hacks maybe?..) [hM02], [hM34], [hM04], [hFFE].. etc (Hacks maybe?..) [T-Eng1.0], [T-Swed1.0] (Translated roms?) [t], [t1], [t2].. (Translated roms?) What i believe is in brackets ). If you can answer my questions you are the best!!! ;D
they arent extensions, they're tags. (!) signifies a confirmed good dump, , and I believe you're right about the translated ones. (rev) indicates different revisions (versions) of the game.