| AAF | American Advertising Federation |
|---|---|
| ACP | Administration Control Panel |
| ADD | Administration on Developmental Disabilities |
| ADI | Advanced Distance Integration |
| ADO | Air Defense Operations |
| ADO | Assistant Director of Operation |
| AEC | atomic Energy Corporation (skr.) |
| APEC | asian-pacific economic cooperation (skr.) |
| APEC | Asian-Pacific Economic Cooperation, Ázijsko-tichomorská spolupráca (angl.skr.) |
| APOLLO | Apache Point Observatory Lunar Laser-ranging Operation |