| Extension | Description | File Type |
|---|
| r | R Script File | Developer Files |
| ra | Real Audio | Audio Files |
| ram | Real Audio metafile | Audio Files |
| rar | RAR File | Archived Files |
| ratdvd | ratDVD DVD Image File | Disk Image Files |
| raw | Raw Data File | Graphic Files |
| rb | Real Basic File | Developer Files |
| rbf | Windows Installer Rollback File | Backup Files |
| rbs | Windows Installer Rollback Script file | Backup Files |
| rc | Visual C++ Resource Script File | Developer Files |
| rcf | Colin McRae Configuration File | Game Files |
| rcf | Rhapsody Storage File | Audio Files |
| rdata | R Data File | Data Files |
| rdb | Redis Database File | Data Files |
| rdf | Resource Description File | Settings Files |
| rec | Recorded File | Video Files |
| reg | Registry File | Settings Files |
| regtrans-ms | Windows Registry Recovery Files | Backup Files |
| rels | Microsoft Office 2007 Relationships | Desktop Publishing |
| rem | Encrypted Data File | Misc Files |
| rep | GTA Replay File | Game Files |
| req | FidoNet Request File | Misc Files |
| res | Compiled C, C++ resource File | Developer Files |
| resume | WinWay Deluxe Resume File | Layout Files |
| resx | Resource File | Misc Files |
| rez | Escape Velocity Nova Plugin File | Game Files |
| rfl | Roll Forward Log File | Backup Files |
| rhp | Rhapsody Notation Program File Format | Misc Files |
| rif | Raster Image File | Graphic Files |
| ris | Research Information Systems Citation File | Text Files |
| rm | RealMedia | Video Files |
| rms | Secure Real Media File | Video Files |
| rmskin | Rainmaker Skin File | Misc Files |
| rmv | Radical Entertainment Video File | Video Files |
| rmvb | Real Media video file | Video Files |
| rnd | RandomSeed File | Misc Files |
| rom | Read Only Memory File | Misc Files |
| rpf | GTA IV Data Package File | Game Files |
| rpl | ARMovie File | Game Files |
| rpm | RPM Package Manager File | Archived Files |
| rpt | Report File | Data Files |
| rrr | Registry Mechanic Backup File | Backup Files |
| rsc | Compiled Resource File | Settings Files |
| rsd | RealSQLDatabase File | Data Files |
| rsm | WinWay Deluxe Resume File | Layout Files |
| rsrc | Mac OS Resource Fork File | System Files |
| rtc | Live Meeting Connection File | Misc Files |
| rtf | Rich Text Format | Text Files |
| rtm | Real Tracker Module File | Audio Files |
| rtp | Turbo Tax Update File | System Files |
| ru | JavaSoft Library File | Web Files |
| run | Runscanner Saved File | Misc Files |
| rus | Navitel Navigator Binary Map File | Geographical Files |
| rv | RealVideo Video File | Video Files |
| rvb | Rhinoscript File | Developer Files |
| rw2 | Panasonic RAW File | Misc Files |
| rwg | Random Word Generator List File | Misc Files |