| 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 |
| aev | Notepad++ Data |
| aexpk | PGP Armored Extracted Public Key Data |
| af | Serif 3DPlus Model |
| af0 | PocketBook Bookmark Data |
| 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 |
| afo | Advanced File Organizer Catalog Data |
| afo | Altair FEKO ADAPTFEKO Frequency Results Data |
| afp | Alphacam Flame Post Data |
| afpk | Audfprint Audio Fingerprint Peaks Data |
| afploc | Mac OS X Finder AFP Location |
| afpp | Mac Apple Share Prep Data |
| afpt | Audfprint Audio Fingerprint Data |
| afr | Arachni Framework Report |
| aft | Ancestry.com Family Tree Database |
| afu | NX Motion Simulation-RecurDyn Function |
| afw | iGrafx FlowCharter Workspace |
| afz | Ancestry.com Family Tree Database Backup |
| afzplug | Corel AfterShot Pro Plug-in |
| ag4 | Microsoft Access G4 Data |
| aga | ArcGIS ArcGlobe Data |