| bckup | Time Machine Backup Data |
| bcl | Illumina CASAVA Base Call |
| bcm | Adobe Bridge Cache Data |
| bcm | Microsoft Office Business Contact Manager Data |
| bcm | Microsoft Works Communications Script Backup |
| bcmap | Adobe Acrobat Binary Character Mapping Data |
| bcmdl | Nintendo 3DS BCMDL Model Data |
| bcml | Biological Connection Markup Language Document |
| bcmr | BC Framer Data |
| bcmx | Microsoft Office Business Contact Manager Customization |
| bcp | Microsoft SQL Server Data Replication Data File |
| bcpkg | Beyond Compare Settings Package |
| bcs | BusinessCards MX Style |
| bcss | Beyond Compare Snapshot Data |
| bct | Adobe Bridge Thumbnail Cache |
| bctpuri | Vuze BCTP URI Data |
| bcuri | BitComet URI Data |
| bcx | Beam-Report Standard Definition Data |
| bcz | Siemens Teamcenter Zipped Briefcase File |
| bd2 | Lacerte Tax Data |
| bd3 | Lacerte Tax Data |
| bd4 | Bridge Designer 4 Data |
| bdb | Blaise Database |
| bdb | Intuit QuickBooks Timer Backup Data |
| bdb2 | Skillpipe Reader Course Data |
| bdc | Babylon Dictionary Data |
| bdc | SmartWare Word Processor Backup Data |
| bdct | BBEdit Dictionary Data |
| bdd | CARA Sound Radiation Data |
| bde | PTC Creo BDE File |
| bdf | Nastran Bulk Data |
| bdf | Oasys T/HIS Bulk Data File |
| bdf | SmartWare Backup Definition Data |
| bdg | Badge Designer 2000 Data |
| bdi | PTC Creo BDI File |
