| aoi | Microsoft Dynamics AX Application Object Index |
| aol | America Online |
| aplg | Audials One Plug-in |
| apln | Adobe InDesign Plug-in |
| aplp | Audials One Plug-in Package |
| appdownload | AppStore Partially Downloaded App |
| appimage | AppImage Image |
| aqq | AQQ Plug-in |
| aria2 | aria2 Control Data |
| artask | BMC Remedy User Tool Shortcut |
| asl | Adobe Photoshop Layer Style |
| ast | ASTree Program |
| asv | Adobe Photoshop Selective Color |
| atf | Adobe Photoshop Transfer Functions |
| automaticdestinations-ms | Windows Jump List |
| ava | Adobe Photoshop Variations File |
| avastlic | Avast! License |
| avastvpn | Avast SecureLine VPN License Data |
| avh | Pioneer AVH Firmware Update |
| awc | Emulex AWC Firmware Update |
| axx | AxCrypt Encrypted File |
| backup | Backup Copy File |
| bak | Backup Copy File |
| bash_profile | Bash Interactive Login Shell |
| bcs | Sonic Foundry Batch Converter Script |
| bea | BEA WebLogic Platform License |
| beb | EEC Analyzer Data |
| bem | Babel Enterprise Module |
| bfe | Bcrypt Encrypted Data |
| bfu | Brute Force Uninstaller Script |
