dirt 3 ctf ctf editor

Hello to everyone....i recently tried to edit the mustang gt (mus) and the hummer 3 (hh3) with ryders ctf editor....i can edit almost any car and i do this for years so its not that im noob....hummer3 has 3 ctfs..hh3.ctf , hh3_A.ctf , hh3_B.ctf...i dont know what exactly each one represents so i...