| bit | DROPS Simulator Drillbits Data |
| bit | Xilinx Bitstream Data |
| biv | IsoBIVMV Data |
| bix | Biblook Index Data |
| bjb | z/VSE System Binary Job Data |
| bjf | NTI Backup Now Backup Job |
| bjg | DESQview Data |
| bjk | Blaise Database BJK Data |
| bjs | Moldex3D Batch Job Settings Data |
| bk0 | Aspen HYSYS Backup File |
| bk1 | Aspen HYSYS Backup File |
| bk1 | FlashGet Database Backup |
| bk2 | FlashGet Database Backup |
| bk2 | Aspen HYSYS Backup File |
| bk3 | FlashGet Database Backup |
| bk4 | FlashGet Database Backup |
| bka | Oracle Enterprise Manager OMS Backup Data |
| bkb | VariCAD Block File |
| bkj | Symantec Backup Exec Job |
| bkl | KeyCarbon Binary Keystroke Log |
| bkmk | Yummy FTP Pro Bookmark |
| bkp | Steinberg WaveLab Backup Plan |
| bkr | BK ReplaceEm Fileset |
| bksln | Freescale BeeKit Solution File |
| bkt | Zortech 3 Tools Samples Data |
| bku | Sage Timeslips Backup |
| bkup | Groundspeak Wherigo Backup File |
| bky | SmartWare Backup Keyboard Data |
| bla | Blaise Datamodel |
| blb | Act! Blob Data |
| blb | Treepad Database Blob Data |
| blend1 | Blender Document Backup |
| blend2 | Blender Document Backup |
| blf | MasterWorks Data |
| blf | CLFS BaseLog |