| a15 | ARJ Compressed Archive |
| a16 | ARJ Compressed Archive |
| a17 | ARJ Compressed Archive |
| a18 | ARJ Compressed Archive |
| a19 | ARJ Compressed Archive |
| a20 | ARJ Compressed Archive |
| a21 | ARJ Compressed Archive |
| a22 | ARJ Compressed Archive |
| a23 | ARJ Compressed Archive |
| a24 | ARJ Compressed Archive |
| a2r | KittyXplorer Encrypted Archive |
| aaf | Apple Archive Format File |
| aar | Android Library Project. |
| ab | Android ADB Backup Archive |
| abu1 | Asus ZenFone Backup Archive |
| ace | WinAce Archive |
| adsm | Advanced Split Machine Split File |
| aes | AES Crypt Encrypted |
| afa | Astrotite 200X Archive |
| afi | AOMEI Backupper Backup Archive |
| afs2 | CRIWARE AWB Package |
| afs3 | Advanced File Security 3 Encrypted Data |
| air | Adobe AIR Installation Package |
| aja | AJC Active Backup Archive |
| akt | AKT Compressed Archive |
| alz | ALZip Archive |
| ants | Tansee Message Transfer Backup |
| apk | Android Application Package |
| aplib | aPLib Compressed Data |
| appv | App-V Virtual Application Package |
| arc | LH ARC Compressed Archive |
| arc | FreeArc Archive File |
| arduboy | Arduboy Game Package |
| arj | ARJ Compressed Archive |
| ark | PowerDesk Pro Archive |