| ann | ENVI Annotation Data |
| ann | Windows Help Annotations |
| annot | Adobe Digital Editions Annotations Data |
| annot | FreeSurfer Annotation |
| ano | Vaa3D ANO Data |
| anp | Annotis Mail Data |
| ans | HotDocs Answer |
| ansa | LS-OPT ANSA Morph Data |
| ansr | AnswerTool Answer Data |
| ant | Radio Mobile Antenna Definition |
| ant | Xilinx ISE ANT File |
| anw | Anno Wallet Backup File |
| anx | HotDocs Answer |
| any | AnyRail Layout Plan |
| anydvd | AnyDVD Registration Data |
| anydvdhd | AnyDVD HD Registration Data |
| an_ | Compressed Windows Animated Cursor |
| aoa | Adaptive Optics AOA Data |
| aoc | IBM Tivoli Network Manager AOC File |
| aod | Microsoft Dynamics AX Application Object Data |
| aodl | Microsoft OneDrive Client Log |
| aof | Artlantis Object File |
| aom | Adobe After Effects Output Module |
| aom | openEHR Archetype Object Model |
| aop | O&P Industry AOP Data |
| aot | Novell Application Object Template |
| aov | ASReml ANOVA Calculations Data |
| ap11 | Siemens TIA V11 File |
| ap2 | ActivPrimary Resource |
| ap5 | Koyo Screen Creator 5 Transmission File |
