Visible crew/equipment: In the opening scene where General Clayton is explaining the 4077 to the psychiatrist, the scene changes to the outdoor set and the camera pans to the right. As the camera pans past the hospital, a white 1970s era shuttle van can be seen driving into the set in the upper right corner of the screen. (00:01:35)
Visible crew/equipment: While in the mess tent, when Henry introduces Hildebrand to Margaret it cuts to Henry as he says that she's the best head nurse in Korea, and at the top right corner we can see the open edge of the tent set and what's behind it.
Visible crew/equipment: After we hear General Clayton in the voiceover talking about how it sometimes seems like Henry is Radar's clerk, during this scene in Henry's office we can see the shadow of moving film equipment - likely the boom, at the top, left side of the screen.
Visible crew/equipment: Right after the opening credits, in the first shot as the words "Directed by Jackie Cooper" appear onscreen, the shadow of the moving boom mic can be seen at the top, left side of the screen.
Visible crew/equipment: In the swamp, behind the General, you see a hole in the tent that disappears a second later. In that second, you see a boom mike.
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.