| Acronym | Meaning |
| CA | California (postal Symbol) - Canada (FIPS 10-4 Country Code; ISO 3166 Digram) - Catalonia -Civil Affairs - Close Armour - Computer Associates - Counter-Air |
| AT | Attotesla |
| COROT | COnvection |
| MARCENT | United States Marine Forces Central Command |
| YM | Yoctometre |
| FOS | Florida Ornithological Society - Full Operational Status |
| CBT | Cognitive Behaviour Therapy -Combat |
| YSA | Youth Service America - Young Socialist Alliance |
| POS | Point Of Sale Terminal /Retail Industry Transaction Computers. |
| FAS | Federation Of American Scientists - Fetal Alcohol Syndrome |