| rrp | Running Time Logger Profile |
| rrp | Rhythm Rascal Project |
| rrr | Registry Mechanic Backup |
| rrt | Rhapzode Resource Template |
| rrx | IBM Datacap Defines Data |
| rs8 | ProSource Data |
| rsd | Resort Software Database |
| rsd | RuneScape Demon Data |
| rsdb | Resort Software Database |
| rsdf | RapidShare Downloader Format File |
| rsdo | Reflection Desktop Customization Rules |
| rsds | Report Server Data Source |
| rse | RockSim Engine Database |
| rsf | WAsP Resource Data |
| rsm | CCNA Network Visualizer Data |
| rsr | Poser Model Preview |
| rst | ANSYS Results Data |
| rstp | ANSYS Results Data |
| rsu | OS/2 Warp Remote Software Update |
| rsw | R&R ReportWorks SQL Report Writer Report |
| rsy | FLEXIT Multishot Survey Raw Data File |
| rt1 | SAS/GIS TIGER Basic Data Record |
| rt2 | SAS/GIS TIGER Shape Coordinate Points |
| rt4 | SAS/GIS TIGER Index to Alternate Feature Names |
| rt5 | SAS/GIS TIGER Feature Name List |
| rt6 | SAS/GIS TIGER Additional Address and ZIP Code |
| rta | Adobe RoboHelp RTA Data File |
| rtc | BrainVoyager QX Regions-of-interest TC Data |
| rtd | Retina Network Security Scanner Output |
| rtda | Microsoft Enterprise Voice Route Helper Data |
