| bfa | Blowfish Advanced CS Encrypted File |
| bff | AIX Backup File Format |
| bh | BlakHole Archive |
| bhx | BinHex Encoded Archive |
| bkc | Backup4all Backup Catalog |
| bkf | Windows NT Backup Archive |
| bko | BackupOutlook Backup Archive |
| bkpi | Synology Hyper Backup Image |
| bks | Windows NT Backup Selection |
| bldl | BenchLink Data Logger 3 Package |
| bli | Blink Archive |
| bma | BMA Archiver Compressed Archive |
| bnh | BinHex Encoded Archive |
| bnhq | BinHex Encoded Archive |
| boa | BOA Constrictor Compressed Archive |
| boz | BZIP Over ZIP Compressed Archive |
| bqy | Shrinkit NuFX Archive with BLU Header |
| br1 | Total Commander Cached Button Bar Icons |
| br2 | Total Commander Cached Button Bar Icons |
| brainzip | Personal Brain v6 BrainZip Archive |
| btc | Becker Tools Compressed Archive |
| btinstall | uTorrent Install Package |
| bu | SAP Business One BackUp Data |
| bulk | BulkZip Compressed Archive |
| bundle | Git Bundle Archive |
| bxpck | BoxedApp Package |
| bxy | Shrinkit NuFX Archive with Binary II Header |
| bz | BZip Compressed Data |
| bz2 | BZip2 Compressed Data |
| bza | IZArc BGA Archive |
