| Acronym | Meaning |
| NWT | Nonwatertight |
| EDV | Electronic Depressurizing Valve |
| MECF | Main Engine Computational Facilities |
| MTCU | Magnetic Tape Control Unit |
| FCOS | Flight Computer Operating System |
| FML | Fault Message Line |
| MCC-DOD | Mission Control Center-DOD |
| PRR | Parts Replacement Request |
| COMB | Combustion |
| SC | Service Charge |