| Acronym | Meaning |
| PI | P?li Language (ISO 639-1 Code) |
| TTTEAF | Thomas The Tank Engine And Friends |
| RFA | Restrictive Fire Area (military) - Royal Field Artillery |
| PACOM | (U.S.) Pacific Command |
| NOC | UK. National Oceanography Centre |
| TW | Republic Of China (Taiwan) (ISO 3166 And FIPS 10-4 Country Code Digram) - Terawatt |
| NIU | Niue (ISO 3166 Trigram) |
| J2 | Joint Intelligence Directorate |
| BHS | British Home Stores |
| WNA | World Nuclear Association |