RETRO Bobby Spencer and RETRO SUPPORT Bob Davis (a backroom SSR person whose technical capability is comparable to John Aaron's) wants to send FIDO Bill Stoval some data to help him answer an inquiry he received from NORAD. There is a problem, however, and it's nothing to do with the data, but rather the ingenious method that NASA built into the MOCR to help mail documents from one room to another - the pneumatic tube (P-tube) system.
Each engineer's console is fitted with a P-tube station, which is assigned a simple one or two-digit number.
Bill Stoval, the FIDO who was on duty for three burns during Apollo 13 -- MCC2 in translunar coast, the PC+2 abort burn in circumlunar space, and MCC5 in transearth coast -- is currently working his most "lax" shift in the MOCR, with both crew and MOCR practically on standby while the entry procedures are being finished up. He is nonplussed when asked to give his station's number.
Link:
https://apolloinrealtime.org/13/?t=125:12:35&ch=19