| AAT | American Accent Training |
|---|---|
| ABT | Air Combat Training |
| ATC | Air Training Command |
| ATC | Air Training Corps |
| ATC | Athletic Trainer Certified |
| ATC | Autodesk Authorised Training Centre (skr.) |
| ATC | Automatic Train Control |
| ATTO | Assistive technology training online |
| CLT | Canterbury Language Training |
| CLT | Central Law Training |