| rgp | RealArcade Game Package |
| rgrp | Avid Pro Tools Region Group File |
| rgss | RPG Maker XP Game Archive |
| rgt | Intuit Quickbooks Temporary File |
| rguninst | RealArcade Uninstall Script |
| rgv | Borland Caliber Requirement Grid Filter |
| rh7 | PCAnywhere Remote History Log |
| rha | Adobe RoboHelp AIR Help Project |
| rhd | Standard Intan RHD2000 Header Data |
| rhf | Adobe RoboHelp for FrameMaker Project |
| rhm | Deep Exploration Material Data |
| ri | Lotus 1-2-3 Data File |
| rib | RenderMan RIB Data |
| rif | FRAMES Receptor Intakes File |
| riff | Resource Interchange File Format |
| rinex | Receiver Independent Exchange Format Data |
| rio | OMICRON Test Universe RIO Object |
| rir | RIR Statistics Exchange Format Data |
| rit | DriveClone Data File |
| riv | CRiSP Harvest Data |
| rjt | RealJukebox Track Info Style |
| rki | Race-Keeper Video Index Data |
| rkl | VST-AU Alpha JUNO Editor License Key Data |
| rkn | Reckon Personal Plus Backup Data |
| rkp | RemoteKeys Profile Data |
| rkplr | NI REAKTOR Player Data |
| rks | SOBEK Rainfall Series Data |
| rky | SDLX Registration Key Data |
| rl7 | PCAnywhere Remote Session Log |
| rld | RecLoad Definition |
| rlg | RegCleaner Language File |
| rlhead | CrazyTalk Head Data |
| rlist | PLINK Rare Genotype List File |
| rlmt | ShockLine MS46121A Ripple Limit Data |
| rlo | Reflection Desktop Layout Data |