| Abbreviation | Definition |
|---|---|
| APT | Advanced Persistent Threat |
| APTY | APpropriation TYpe |
| AQ | Al Qaida |
| AQC | Administrative Quality Control |
| AQSIQ | Administration of Quality Supervision Inspection and Quarantine |
| AR | American Revolution |
| AR | Automatic Rejection |
| ARA | Area Redevelopment Administration |
| ARB | Architecture Review Board |
| ARBA | Army Review Boards Agency |
| ARC | Agricultural Resource Center |
| ARC | Alien Residents Card |
| ARC | Appalachian Regional Commission |
| ARC | Appalachian Regional Committee |
| ARCTIC | Arctic Research Commision |
| ARD | Annual Review Database |
| ARDA | Appalachian Regional Development Act |
| ARDC | Attorney Registration Disciplinary Commission |
| ARDC | Attorney Registration & Disciplinary Commission |
| ARF | Area Resource File |