Other mistake: When they're playing poker, Hawkeye is sitting at an angle so that Sgt. Baker cannot see the earpiece that Hawkeye is wearing. However, Hawkeye sometimes turns his head enough for us to see his ear and, since the camera angle is over Baker's shoulder, Baker must have been able to see the earpiece too and realise he was being cheated. (00:13:20)
Continuity mistake: While Radar's spying on Baker's hand for Hawkeye during the poker game, Baker's only wearing his T-shirt later in the game, but in the views from Radar's telescope eyepiece Baker's still wearing his jacket.
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.