The patrol cap, formerly called the battle dress uniform (BDU) cap, is a visor style with a circular crown and retractable earlaps, which is the same basic design as the M-1951 cotton field cap. It was intended for wear with the temperate battle dress uniform.
The temperate battle dress uniform (BDU) was introduced as the Army's field and garrison uniform on 1 October 1981. The temperate BDU has a woodland camouflage pattern, infrared reflection, and reinforced elbows, knees, and seat in a 50-50 cotton-nylon fabric. The temperate BDU is part of the Army's battle dress system (BDS), which includes four camouflage subsystems allowing the Army to operate in temperate, desert, tropical, and arctic environments.