| AAB | Associació Aquariòfila de Barcelona |
|---|---|
| AAS | Advances in the Astronautical Sciences |
| AAS | American Astronautical Society |
| ABS | alkylbenzénsulfonát (skr.), skupina tenzidov |
| ACI | alliance Cooperative Internationale (skr.) |
| ACT | Additional Centre Tank |
| ADD | Army Data Dictionary |
| ADI | académie diplomatigue internationale |
| ADK | Additional Decryption Key |
| AED | Academy for Educational Development |