@Ronflaix
Tbh the only ones of any real concern are the ones for what region (usually capital letters, like F for French, U for US, E for European - I think S is Spanish), ! Meaning "known good dump", h for romhack, and t for translation patched. I think b might be "bad dump" but it also could be "bootleg"
@Nine haaa, thanks for the additional info like h and b, thanks! :D
@Ronflaix
That and I raided old games for useful backgrounds and sprites for my sprite comic. ^^;;