| Abbreviation | Definition |
|---|---|
| ARF | Autonomous Reflection Form |
| ARG | Autodesk Resource Guide |
| ARGM | Assistant Restaurant General Manager |
| ARID | Active Reviews for Intermediate Designs |
| ARK | Advanced Rendering Kernel |
| ARL | Abbreviated Rule Language |
| ARM | Advanced RISC Machine |
| ARN | Amazon Resource Name |
| ARPA | Adaptive Resource Protection Agent |
| ARPA | Advanced Research Projects Agency |
| ARPANET | Advanced Research Projects Agency Network |
| ARS | Attend Read Skip |
| ART | Anthropomorphic Robotic Testbed |
| ARU | Audio Response Unit |
| AS | Activity Start |
| AS | Application System |
| AS/RS | Automated Storage and Retrieval System |
| AS1 | Applicability Statement 1 |
| AS2 | Applicability Statement 2 |
| ASAP | Ada Source Analysis Program |