| Acronym | Meaning |
| CES | Crew Escape System |
| MF | Medium Frequency (300 To 3000 KHz) |
| RTC | Real-Time Command |
| SHDN | Shutdown |
| SST | Subsystem Terminal On Spacelab |
| NATL | National |
| CDB | Central Data Buffer |
| MADS | Modular Auxiliary Data System |
| MTCU | Magnetic Tape Control Unit |
| FMOF | First Manned Orbital Flight |