| accfl | Microsoft Access Field Template |
| accft | Microsoft Access 2007 Data Type Template |
| adb | Ability Database Document |
| add | Alphacam Diecut Drawing |
| ade | Microsoft Access Project Extension |
| adoc | AsciiDoc File |
| ados | ADOS Compound Document |
| adox | ActivDox Document |
| adsk | Autodesk Exchange File |
| ad_asm | Alibre Design CAD Assembly Document |
| ad_bom | Alibre Design Bills of Material Data |
| ad_drw | Alibre Design 2D CAD Drawing |
| ad_prt | Alibre Design CAD Part Document |
| ae | SoftQuad Author/Editor Document |
| aed | Alphacam Wire EDM Drawing |
| aeh | EBooksWriter E-book Document |
| af2 | Micrografx ABC FlowCharter 2 Document |
| af3 | Micrografx ABC FlowCharter 3 Document |
| afd | Alphacam Flame Drawing |
| afdesign | Affinity Design Document |
| aff | BART Animated File Format |
| afpub | Affinity Publisher Document |
| agn | Psion Series 3 Agenda Document |
| agp | Aspen Graphics Workspace |
| agz | AggFlow Aggregate Plant Flow Diagram |
| aht | AH Note Text Document |
| aib | ArcInfo Binary Coverage |
| aig | Abracadata Drawing |
| ait | Adobe Illustrator Template |
| ajd | Alphacam Water Jet Drawing |
| ak | TracerCAD File |
| al3d | Alicona Imaging AL3D File |
| ala | Alan IF Document |
| ald | Alphacam Laser Drawing |
| all | Lotus 1-2-3 Worksheet Formatting Data |