| Acronym | Meaning |
| PJ | Picojoule |
| NAM | Namibia (ISO 3166 Trigram) |
| GMT | Giant Magellan Telescope - Greenwich Mean Time |
| 4D | Four-dimensional (usually Three Spatial Plus One Temporal Dimension |
| NGO | Non-Governmental Organization |
| CALL | (U.S.) Center For Army Lessons Learned |
| FFC | Free For Chat |
| BTU | British Thermal Unit |
| ARM | Anti-Radiation Missile -Armenia (ISO 3166 Trigram) |
| TIBS | Tactical Information Broadcast System |