Revealing mistake: The first scene is set in the X-Ray room. There is an X-Ray up on a lightbox in the background. Towards the end of episode 14, there is a scene in the O.R. - the exact same X-Ray is visible in the background there as well. (00:45:00)
Continuity mistake: As the camera looks at the door of the Officer's club while the General and Hawkeye talk, other tents can be seen behind them. As Hawkeye brings in the enlisted personnel, the area is totally empty.
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.