| Abbreviation | Definition |
|---|---|
| AAA | Army Security Agency |
| AAG | Assistant Attorney General |
| ACIP | Aerosol Climate Interactions Program |
| ACSI | Americas Counter Smuggling Initiative |
| AD | Assistant Director |
| ADEX | Administrative Index |
| ADIC | Assistant Director In Charge |
| ADM | Administrative |
| AEAA | Atomic Energy Act Applicant |
| AEAE | Atomic Energy Act Employee |
| AFSA | Armed Forces Security Agency |
| AI | Agitator Index |
| AIR | America's Investigative Reports |
| AIRS | Access To Information And Reading Services |
| AL | Albany Field Office |
| AMSD | Air Mail Special Delivery |
| AN | Anchorage Field Office |
| AO | Auxiliary Office |
| AP | Anti-Patriotism |
| ARL | Anti-Riot Laws |