Understanding wartime ranks and their insignia can be helpful when identifying individuals in photographs.  Field promotions were were not unusual during the course of one's tour of duty, and rank can also be used to establish the approximate date of some photographs (or at the least a chronological order within a collection).

The Air Force became a separate branch of the armed forces in 1948, and during the 1950s adopted its own rank and grade structure for enlisted men.  Prior to that time, the Army Air Force used the same ranks and insignia as the U.S. Army (which have also changed slightly in the intervening years).