| A4O | označenie lietadiel Ománu, Omán (označenie lietadiel) |
|---|---|
| AAC | rakúsky automobilový klub |
| AAD | Atomic Absorption Detector |
| AAD | Automatic Activation Device |
| AAE | automatic answering equipment (skr.) |
| AAF | Audit Automation Facilities |
| AAS | Allround Automotive Solutions |
| AAS | American Astronomical Society |
| AAS | Astronomischer Arbeitskreis Salzkammergut |
| AAS | Atomic Absorption Spectrophotometry |