| r2lic | Rainlendar v2 License Data |
| r2skin | Rainlendar Skin |
| r3f | SAP R/3 Form Data |
| r8 | Cubicomp PictureMaker Red Channel Image Data |
| r99 | MicroStation Modification System Resource File |
| raa | RiTE Ascii Animation |
| rab | Encyclopaedia Britannica 2002 Deluxe Data |
| rac | Racter Conversation Data |
| rac | UltraEdit Autorecovery Data |
| rac | Venue Race Application Race Data |
| rad | RFM Radiance Spectrum File |
| rag | RAM Advanse Data File |
| rai | SPEFO Stellar Spectra Analysis Data |
| ral | Atlas Right Track Layout |
| ral | WinRail Layout Data |
| ram | RiTE Ascii Model |
| rap | GSM Returned Accounts Procedure Data |
| raq | Cobalt RAQ Backup Data |
| ras | RiTE Ascii Shader Information |
| rat | Nimbus 7 SAMS CRAT File |
| rat | PICS Service Description |
| raw | Bruker RAW Data |
| rawpkt | Colasoft Capsa Capture Data |
| ray | Altair FEKO POSTFEKO Rays Data |
| ra_ | Resco Photo Viewer Thumbnail Cache |
| rb1 | R:Base v4.5 Database |
| rb2 | R:Base v4.5 Database |
| rb3 | R:Base v4.5 Database |
| rba | RegexBuddy Action Data |
| rbc | Retrospect Backup Catalog |
| rbf | Altera Raw Binary File |
| rbf | RBase Data |
| rbg | RegexBuddy GREP Action Data |
| rbh | Adobe RoboHelp Data |
| rbi | eBahn Reader Data |