| rtstn | Audials Station Data |
| rtsx | Royal TS v2 Document |
| rttex | Proton Texture Data |
| rtwsh | Audials Radiotracker Wishlist |
| ru | Java Russian Font Properties Data |
| ruel | Revo Uninstaller Pro Data |
| ruf | WRAP Regulated-unappropriated Flow Adjustment Data |
| rui | SPEFO Rectified Spectrum Data |
| ruj | Oracle Database Recovery-Unit Journal |
| ruk | Recorder 6 Rucksack Data |
| run | Runscanner Scan Result |
| rup | IBM Rational Unified Process Data |
| rut | Novapoint Grid File |
| rv3 | NewsBin Pro Header Storage |
| rv4 | NewsBin Pro Header Storage |
| rv7 | Reason RV7 Data |
| rvk | GnuPG Revocation Key File |
| rvm | AVEVA Plant Design Management System Model |
| rvn | RVN Data |
| rvp | CNET CatchUp Data |
| rvq | Autodesk CFD Radiation Data |
| rvw | ReviewMate Review Data |
| rvz | AVEVA Review 3D Model |
| rw3 | RapidWeaver 3 Site |
| rw5 | Carlson 2016 RAW Data |
| rwb | RefWorks Backup File |
| rwc | WAsP Regional Wind Climate |
| rwcx | Trimble SX10 Scanned Points Data |
| rwd | NRG Symphonie Logger Raw Data |
| rwf | Gaussian Read-Write File |
| rwf | ReFrame Workspace |
| rwpat | RockWorks Pattern Tables Data |
| rws | Retina Wireless Scanner |
| rx | Borland Reflex Database Driver |
| rx1 | R:Base X.5 Database |