ah well that is what I wanted to know, how I can spot them, as chthulu's says realism and IS, but another one says realism and they just mean FF!

But to answer the question as to what does it do, as near as I can tell, it limites the number of grenades to 3 (or is this up to the op?) which is much more realistic as GI was 2 frag grenades and one phosphorus or other special grendade.

But the main thing is that a shot to the torso will bring you down most of the time just like a head shot does in the regular mod.

So will shots to the legs and arms too at times. Which is very realistic. A .45 colt pistol was designed to stop a charging horse, for heaven's sake. A thompson, even if it hit you in the arm, would knock you down probably put you out of comission - which is what combat was all about really, not killing the enemy but making him unable to continue to make war.

Anyway, I find it much more rewarding playing the realism mod where you can bring someone down with one good shot from an M-1 from 300 yards away, and wear the MP-40 and the Thompson cut you to ribbons at close range.