-2 with what kind of shot? TAG and LTAG only affect homing artillery(AS, p 75), laser-guided bombs(which do get a -2) (AS, p 79), LRM attacks with semi-guided ammo(LRM-only shots do get the -2, standard shots do not) (AS, p 80), or air-to-ground capital or sub-capital attacks(they get a -2) (AS, p 87).