I have a japanese Capcom VS SNK 2 gd-rom, and the number is GDL-0007A? Would that mean that there's a "B" version, or is this just some numbering system with the goal of confusing everyone?
I'm not sure hexadecimal has anything to do with this. If that was the case, you would see GDL-00071, 00072, and so on. When there is a revision, it is marked on the disc with the title, or can be seen while the game is running. This likely has to something with regions.