Factual error: In this episode, the regulars receive and respond to letters from a Fourth-Grade class in Hawkeye's home town. Charles receives one from a little girl who says she's sent him a birch leaf. Unfortunately, the leaf he removes from her glassine envelope is a maple leaf. (Note: there was no indication that this was supposed to be her mistake.)
Visible crew/equipment: While Hoops Potter is going for the camp record in free throws, in overhead shots with everyone encircling the 'basketball court' - particularly right after free throw 28 and after Potter says that he feels like a sideshow freak, the boom can be seen moving around right beside the hoop's post at the top, left side of the screen.
Visible crew/equipment: While Hawkeye, BJ, and Charles are in the Swamp reading the letters, when BJ says, "Leave it to Charles to be the world's first poison pen-pal," the shadow of the boom mic can be seen moving around at the top right corner of the screen.
Visible crew/equipment: While BJ, Hawkeye, and Charles are in the Swamp, when BJ starts reading the letter from the child who thinks the army is like camping out Charles takes that letter away from BJ, and just as Charles is about to sit back down the edge of the Swamp set can be seen at the top right corner of the screen.
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.