When ever you see photos or videos of real war, or even enactments, the American troops in particular often appear to have netting placed over the top of their metal helmets. What was this for? Attaching badges or something else important? I know some wedged packs of cigarettes in there, but it surely can't be only for that?
The main purpose of adding netting was to enhance camouflage and decrease the shine of the helmets outer shell. The netting also allowed soldiers to attach foliage to their helmets when needed.
Gordon L. Rottman, World War II Tactical Camouflage Techniques