Gary and Ed, you're talking about two different things. First, they use maintenance codes to describe the condition of the aircraft. Normally, military transports use Alpha 1, 2 or 3 and fighters use Code 1, 2 or 3. Code/Alpha 1 indicates no problems, 2 indicates minor writeups and 3 indicates major problems that will affect the ability of the aircraft to carry out its mission.
Pax codes are listed in section 4-3 of the DoD FLIP General Planning, available at https://220.127.116.11/products/digitalaero/enroute.cfm. In this case, Alpha designates Air Force, 5 designates a Major General (2-star), and 6 designates a Brigadier General (1-star).