| rbf | RBase Data |
| rbf | Retrospect Backup Data |
| rbg | RegexBuddy GREP Action Data |
| rbh | Adobe RoboHelp Data |
| rbi | eBahn Reader Data |
| rbk | Windows 95 Registry Backup |
| rbl | RegexBuddy Library Data |
| rbm | Tekla Structures Reinforcement Mesh Properties |
| rbn | Richard's Bridge Notation Data |
| rbr | libigl ReAntTweakBar Data |
| rbs | R:Base 4000 Database |
| rbs | RealiMation 3D Object |
| rbs | Rutherford Backscattering Spectroscopy Analysis Package Data |
| rbsct | RegexBuddy Source Code Template |
| rbt | Xilinx Raw BIT Data |
| rbtx | Lego Mindstorms NXT Create Pack and Go File |
| rbuistate | Real Studio UI State Data |
| rbv | GrafNav Exported Binary Values Data |
| rbx | RapidBuilder Simulation Data |
| rc1 | Samsung S5230 Firmware RSRC1 File |
| rc2 | Samsung S5230 Firmware RSRC2 File |
| rca | RCA Anaesthetic Logbook Document |
| rcb | Ripple Chat Bot Data |
| rcd | Symantec pcAnywhere Recorded Session |
| rcg | Recog Character Recognition Set |
| rch | MODFLOW Recharge Package |
| rch | SWAT Reach Output Data |
| rci | SPEFO Rectified Cleaned Data |
| rcj | Robocopy Job Data |
| rck | REScheck Data |
