By codes do you mean pushing buttons and getting something? because there are none of those for this game. but i'll give you some tips:
Bandana: 30 dog tags
stealth: 60 for tanker, 120 for Plant section
blue wig(infinite O2): every dog tag
Orange wig(infinite grip): 150 dog tags
Brown wig(infinite ammo): 80 dog tags
ps:ask for anything else Ill try and find it