Visible crew/equipment: After Hawkeye shows up in Colonel Potter's office with severe allergy symptoms, BJ and Margaret walk out with him, and when Potter says, "Time we found out what's on his mind," the shadow of the boom mic moves across the door.
Visible crew/equipment: A crew member is visible in Margaret's tent when she confronts OR nurse Helen about her drinking, approximately halfway through the episode.
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.