| AAM | Aircraft Availability Model |
|---|---|
| AAR | Association of American Railroads, Asociácia amerických železničných spoločností (angl.skr.) |
| ABI | Available Bandwidth Index |
| ABS | meno Abigail |
| ADI | Acceptable Daily Intake |
| ADT | Average Daily Traffic |
| ARF | Acute Renal Failure |
| ARF | Acute Renal Failure (skr.) |
| ARU | skr. american railway union |
| ATA | Allegheny Trail Alliance |