Ryan, Holt, and the soldiers and recruits at Ft. Bliss wear the shoulder patch of the 4th Army - a white four-leaf clover on a red diamond. The 4th Army was activated in 1932 as the U.S. Western Defense Command. During World War II, the 4th Army operated the Louisiana maneuver area, and was credited with training about half the combat units that went overseas.
The horizontal white bars on the rear of Sergeant Ryan and Sergeant Holt's helmet liners indicate they are NCOs (non-commissioned officers). Officers had vertical white bars on the backs of their helmets. The purpose of the markings was to quickly identify those in command from the rear.
Thorne Ryan holds the enlisted rank of Sergeant First Class (E-7), Verne Holt that of Staff Sergeant (E-6), and Ryan's nemesis Opperman is a Master Sergeant (E-8).