| Acronym | Meaning |
| PSO | Peace Support Operations - Primary Standardisation Office (ABCA) - Protocol Supporting Organization (of The ICANN) |
| PA | Panama (ISO 3166 Digram) - Paraguay (FIPS 10-4 Country Code) -Partial Agonist -Pennsylvania (postal Symbol) - Petampere -PolyAmide (Nylon) - Prince Albert Piercing - Public Address (vocal Amplification System) - Public Affairs |
| YL | Yottalitre |
| DNR | Do Not Resuscitate |
| KEDO | Korean Peninsula Energy Development Organization |
| PAYE | Pay As You Earn |
| RI | Rhode Island (postal Symbol) |
| CAM | Chemical Agent Monitor - Computer-Aided Manufacturing |
| HT | Haitian Creole Language (ISO 639-1 Code) |
| CUPW | Canadian Union Of Postal Workers |