| ann | Windows Help Annotations |
| ann | Zemax Annotations Data |
| annot | Adobe Digital Editions Annotations Data |
| annot | FreeSurfer Annotation |
| ano | Vaa3D ANO Data |
| anp | Annotis Mail Data |
| ans | ANSYS Model Data |
| ans | HotDocs Answer |
| ansa | LS-OPT ANSA Morph Data |
| ansr | AnswerTool Answer Data |
| ant | calcAnt Saved Calculation Data |
| ant | Radio Mobile Antenna Definition |
| ant | Xilinx ISE ANT File |
| anv | ActivTrak Net View Data |
| anw | Anno Wallet Backup File |
| anx | HotDocs Answer |
| any | AnyRail Layout Plan |
| anydesk | AnyDesk Session Record |
| anydvd | AnyDVD Registration Data |
| anydvdhd | AnyDVD HD Registration Data |
| anydvd_smsk | AnyDVD Speedmenu Skin 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 |
| aoi | Art of Illusion 3D Scene |
| aom | Adobe After Effects Output Module |
| aom | openEHR Archetype Object Model |
