1.12.3. Initially, the enlisted rank system remained as it had been in the United States Army Air Force. Corporal was removed from NCO status in 1950. Then, in 1952, the Air Force officially changed the names of the lower four ranks from private to Airman basic; private first class to Airman, third class; corporal to Airman, second class; and sergeant toAirman, first class. These changes were in response to a development that surfaced during World War II, and the rank structure would continue to evolve over time. Promotion and specialization went hand-in-hand with training in the new Air Force. When the new organization established Air Force specialty codes as standard designations for functional and technical specialties, qualification for an advanced Air Force specialty code became part of the criteria for promotion. During the late 1940s, the Air Force also began an Airman Career Program that attempted to encourage long-term careers for enlisted specialists.