Visible crew/equipment: When Frank climbs into the jeep belonging to Major General Cornell Dickering, the MPs show up at the same time that BJ and Hawkeye walk up to join the fun, and during this scene there's a T-mark (albeit a dusty one) on the ground at the driver's side of the jeep.
Visible crew/equipment: When Hawkeye removes BJ's Captain rank bars from his uniform and then pins it on Radar's knit cap, in the shot facing Hawkeye and BJ the shadow of the boom mic moves across Radar's back.
Visible crew/equipment: When Hawkeye and Radar are in the jeep heading to Kimpo Air Base they drive past the checkpoint, and in their closeups the camera casts a shadow on the hood of the jeep.
Answer: It is actually Cencompac for Central Command of the Pacific. It is like the headquarters for all military activity in the Pacific Region (Japan, Korea, Okinawa, etc. The newer version of that is United States Pacific Command (USPACOM).
EMTurbo
And the abbreviations were used mainly by the Navy. Especially CENCOMPAC.
Https://en.wikipedia.org/wiki/United_States_Indo-Pacific_Command.