| Abbreviation | Definition |
|---|---|
| ARCA | Advanced Reservation of Capacity Agreement |
| ARCNET | Attached Resource Computer NETwork |
| ARF | Application Roaming Framework |
| ARF's | Agreed Ready for Service |
| ARIN | American Registry for Internet Numbers |
| ARINC | Aeronautical Radio INCorporated |
| ARINC | Aeronautical Radio Incorporation |
| ARK | Address Resolution Key |
| ARM | Atm Router Module |
| ARMPIT | Acquisition Of Responsible Morals And Permission For Internet Transmission |
| ARO | Appliance Replacement Option |
| ARO | Application Resource Optimizer |
| ARP | Active Reservation Protocol |
| ARP | Active Resource Program |
| ARP | Arp Resolution Protocol |
| ARPS | Advanced Routing and Permitting System |
| ARQ | Automatic Repeat reQuest |
| ART | Automated Response Technology |
| AS | Add Subnet |
| AS | Appliance Server |