| adu | Addict Custom Dictionary |
| adw | Adhawin Transliteration Scheme |
| adx | XML-based ADIF File |
| ad_pcf | Alibre Design Catalog Feature Part Data |
| ad_smp | Alibre Design Sheet Metal Parts Data |
| ad_sym | Alibre Design Symbols Data |
| aea | AdWords Editor Archive |
| aeb | Alphacam Wire EDM VB Macro |
| aec | Cinema 4D After Effects Composition |
| aecache | Adobe After Effects Cache |
| aecap | Adobe After Effects Text Template Capsule |
| aedt | ANSYS Electronics Desktop Data |
| aedtz | ANSYS Electronics Desktop Archive |
| aeg | Netmino Data |
| aeix | ARGUS Enterprise Exported Data |
| aek | Adobe After Effects Keyframe |
| aem | STK Azimuth-Elevation Mask |
| aem | Alphacam Wire EDM Param Macro |
| aen | Inventus Antum Secured Mail Encrypted Data |
| aeo | Avid MetaSync Avid Enhancement Object |
| aep | Alphacam Wire EDM Post Data |
| aepkey | Advanced Encryption Package Key |
| aer | Adobe Atmosphere World |
| aero | STK Aerodynamics File |
| aet | Adobe After Effects Template |
| aetx | Adobe After Effects XML Template |
| aeu | Autoroute Express Europe Route Data |
| af | Serif 3DPlus Model |
| af4 | Audifit v4 Data |
| afb | Alphacam Flame VB Macro |
| aff | FRAMES Air Flux File |
| aff | WRAP SIMD Annual Flood Frequency Data |
| afg | Tablet Assembly Data |
| afm | Acoustic Filter Map File |
| afm | Alphacam Flame Param Macro |