| Extension | File Type | Files scanned | Contributor |
| R/G/B/A/P | Img Software Set native bitmap | 5 | |
| R | Rebol source code | 116 | |
| R | Rebol source code (with rem) | 4 | |
| R | Twist Report script | 100 | |
| R2A | Yamaha RS7000 - All data | 2 | |
| R2D | Reflex 2 Database | 10 | |
| R2LANG | Rainlendar 2 Language | 3 | |
| R2P | Yamaha RS7000 - Pattern data | 2 | |
| R2R | Reflex 2 Report | 8 | |
| R2S | Yamaha RS7000 - Song data | 2 | |
| R2SKIN | Rainlendar 2 Skin | 14 | |
| R2X | r2mod profile | 5 | |
| R2Z | Borland Reflex 2 color settings | 5 | |
| R2Z | r2mod Profile package | 5 | |
| R3/R4/MON | Reflections/Monzoom IFF data (generic) | 37 | |
| R3A/R3P | Yamaha RS7000 - Sample data | 3 | |
| R3D | R3D data stream | 5 | |
| R3D | Relux 3D geometry | 6 | |
| R3D | Renderit3d data | 2 | |
| R3M | RealFun 3 Module/song | 55 | |
| R3PROJ | RPG Maker 2003 Project id | 3 | |
| R3V | RealFun 3 Voice bank | 2 | |
| R3W | RealFun 3 sample kit | 5 | |
| R8 | Cubicomp PictureMaker red channel image data | 15 | |
| RA | RealAudio audio | 5 | |
| RA3REPLAY | Red Alert 3 replay | 8 | |
| RAC | Random Access Compression format | 2 | |
| RAC/RAW | Rdos Raw OPL Capture music | 5 | |
| RAD | Microsoft Golf 1.0 for Windows game data | 24 | |
| RAD | Reality Adlib Tracker module | 6 | |
| RAD | Rexx-Adventure game source | 9 | |
| RADIO | Enigma2 radio list | 13 | |
| RAF | Fujifilm Raw image | 14 | |
| RAF | Rich Appearance Format animation | 6 | |
| RAG | RAG-D bitmap | 2 | |
| RAG | TradeStation RadarScreen configuration | 11 | |
| RAL | Power Drive saved game (DOS) | 4 | |
| RAM/ROM | Logisim memory image | 12 | |
| RAM | RealMedia meta file | 4 | |
| RAP | Raptor flowchart | 14 | |
| RAP | Samplitude RAM Project (old ver) | 24 | |
| RAR | RAR compressed archive (gen) | 38 | |
| RAR | RAR compressed archive (v-4.x) | 3 | |
| RAR | RAR compressed archive (v1.x) | 5 | |
| RAR | RAR compressed archive (v5.0) | 3 | |
| RAR | WinRAR interface theme | 9 | |
| RAR | eMule skin profile packages (RAR) | 8 | |
| RARBASE64 | RARBase64 encoded | 4 | |
| RARC | Nintendo RARC archive | 7 | |
| RAS | Max Payne data file | 8 | |
| RAS | Rexx-Adventure Saved game | 6 | |
| RAS | Rigaku XRD RAS format | 6 | |
| RAS/IM1/IM24/IM32/IM8/RAST/RS/SR/SUN | Sun Raster bitmap | 15 | |
| RAT | Houdini Random Access Texture | 12 | |
| RAT | PICS Rating System | 14 | |
| RATDVD | ratDVD DVD image | 4 | |
| RAV | Rave Reports Project | 8 | |
| RAVENPRESET | Raven Pro Preset (JSON) | 4 | |
| RAW | CT Raw disk image | 8 | |
| RAW | DCTV raw bitmap | 4 | |
| RAW/SLD | Finnigan Xcalibur raw data | 5 | |
| RAW | Flipper Zero RAW RFID format | 12 | |
| RAW | Helios raw disk image | 3 | |
| RAW | ImageKnife Raw bitmap | 2 | |
| RAW | KryoFlux Raw stream | 603 | |
| RAW | PlayStation Pocket memory card | 6 | rari-teh |
| RAW | TkImg RAW bitmap | 2 | |
| RAW | Track Attack Raw bitmaps/frames | 29 | |
| RAW | XL-Paint MAX bitmap | 2 | |
| RAWVOX | Raw Voxel format | 2 | |
| RAX | RAX compressed archive | 5 | |
| RB | Rocket eBook | 38 | |
| RB | Rocket eBook (variant) | 2 | |
| RB2 | Rebel spreadsheet (v2) | 9 | |
| RB4 | Resume Builder 4.x | 3 | |
| RBC | Easy Resume Creator Pro resume | 5 | |
| RBD | Reality Bytes game Data archive | 6 | |
| RBF | LEGO Mindstorms EV3 brick executable code | 6 | |
| RBF | Raw Bitmap Font | 6 | |
| RBFRM | REALbasic Form/Window | 31 | |
| RBH | The House of the Dead game data container | 163 | |
| RBJ | Redcode Object XRA PC (v1.x) | 243 | |
| RBN | Richard's Bridge Notation | 14 | |
| RBP | REALbasic/Xojo Project | 54 | |
| RBPACK | RPG Developer Bakin game data archive | 2 | |
| RBS | Propellerhead Software ReBirth Song | 9 | |
| RBT | LEGO NXT Brick | 36 | |
| RBT | Sierra Robot Animation | 18 | |
| RBT | Xilinx ASCII Bitstream | 11 | |
| RBVCP | REALbasic Project | 8 | |
| RBX | Dynamix game data archive | 4 | |
| RBX | Richard's Bridge Notation (inline) | 4 | |
| RBXL | Roblox Location | 35 | |
| RBXLX | ROBLOX XML Place | 20 | |
| RBXM/RBXMX | Roblox Model | 61 | |
| RC | RCFile format | 2 | |
| RC1 | RenderStar-2 Render Control info | 12 | |
| RCAD | RealCADD drawing | 12 | |
| RCC | Qt binary Resource | 4 | |
| RCC | Ricevuta Agenzia delle Entrate (generic) | 32 | |
| RCD | Oloneo HDR preset | 82 | |
| RCD | Oloneo HDRengine project | 5 | |
| RCD | RcCad model | 6 | |
| RCF | ATG Core Cement Format game data archive | 4 | |
| RCF | RadCore Cement library Format game data archive | 4 | |
| RCK | Eko Software game data | 17 | |
| RCL | ReSource Control Language | 2 | |
| RCL | Recolored project | 4 | |
| RCL | Roxio Easy CD Creator Layout/project (v6) | 10 | |
| RCL | Roxio Easy CD Creator Layout/project (v7-) | 9 | |
| RCM | LigPlot Residue Centres-of-Mass data | 4 | |
| RCO | Sony PlayStation Resource Container (generic) | 143 | Masamune3210 |
| RCPROJ | RainCode COBOL Project | 10 | |
| RCPROJ | RainCode COBOL Project (UTF-8) | 4 | |
| RCPROJ | RainCode JCL Project | 3 | |
| RCPROJ | RainCode JCL Project (UTF-8) | 4 | |
| RCPROJ | RealityCapture Project | 12 | |
| RCS | RadDeveloper color scheme | 5 | |
| RCS | Reality Capture Scan data | 2 | |
| RCT | Maxon Resource Creation Tool data | 12 | |
| RCX | Seiko Epson firmware | 3 | |
| RD | R Documentation | 370 | |
| RD | R Documentation (with rem) | 10 | |
| RD/RDF | Reaction Data file | 9 | |
| RD4 | Ray Dream Designer scene | 24 | |
| RDA | Vivado Design Checkpoint RDAFlowver data (v5) | 22 | |
| RDAR | REDengine game data Archive | 4 | |
| RDATA | R saved work space (generic) | 11 | |
| RDATA | R saved work space (v2) | 3 | |
| RDATA | R saved work space (v3) | 2 | |
| RDB | OpenOffice/LibreOffice type library database (UNOIDL) | 12 | Joerg Jenderek |
| RDB | OpenOffice/LibreOffice type library database (XML) | 15 | Joerg Jenderek |
| RDB | Redis RDB format (generic) | 12 | |
| RDB/URD | StarOffice/OpenOffice/LibreOffice registry database | 19 | Joerg Jenderek |
| RDBDATA | Age of Conan game data archive | 2 | |
| RDC | IDRISI Raster image Documentation | 7 | |
| RDF | Friend of a Friend (FOAF) Resource Description Framework | 13 | |
| RDF | Ion Storm Resource Data File | 3 | |
| RDF | Relux project | 23 | |
| RDF | Yaesu radio memory file | 5 | |
| RDG | RDCMan config | 4 | |
| RDI/RIB | RIFF Device Independent Bitmap | 6 | |
| RDL | Descent Level | 46 | |
| RDL/RDLC | SQL Server Reporting Services Report Definition Language | 17 | |
| RDL/RDLC | SQL Server Reporting Services Report Definition Language (UTF-8) | 22 | |
| RDM/README/REA | Readme file info format | 34 | |
| RDOC_OPTIONS | Ruby RDoc Options | 11 | |
| RDP | Remote Desktop Connection Settings | 8 | ptweasel |
| RDP | Remote Desktop Connection Settings (Unicode) | 8 | ptweasel |
| RDQ | Reduq compressed data | 3 | |
| RDS | Ray Dream Studio | 189 | |
| RDT | G-Police game data | 3 | |
| RDV | Magician raster/printer driver | 29 | |
| RDW | Real-DRAW Project | 20 | Flarn2006 |
| REAL | Adobe Aero Experience | 5 | Tyler Thorsted |
| REALITY | Apple Reality Composer format | 12 | |
| REALM | Realm database | 16 | |
| REAPEAKS | REAPER media peak information (v1.0) | 8 | |
| REAPEAKS | REAPER media peak information (v1.1) | 5 | |
| REASON | Reason song | 66 | |
| REC | QuickLink II Fax bitmap | 2 | |
| RECOG | BootX bootblock Recognition data | 5 | |
| RED | RED files library | 45 | |
| RED | REDway DER (Dynamic Elements Resource) | 11 | Kieran O'Donnell |
| RED | Red source code | 180 | |
| RED | Red source code (UTF-8) | 3 | |
| RED | Redcode source | 58 | |
| REDIF/RDF | ReDIF template | 19 | |
| REDSCRIPTS | CD Projekt RED / Cyberpunk 2077 compiled game Script | 8 | |
| REF | Atari ST Guide ref links | 4 | |
| REF | IDRISI raster image Reference | 4 | |
| REF | Lavasoft Ad-Aware reference file | 6 | |
| REG | Windows Registry Data | 11 | |
| REG | Windows Registry Data (Ver. 4.0) | 7 | |
| REG | Windows Registry Data (Ver. 5.0 - UTF16) | 7 | |
| REG | Windows Registry Data (Ver. 5.0) | 4 | |
| REG | Wine Registry | 9 | Joerg Jenderek |
| REKO | REKO cardset (Amiga) | 11 | |
| REL | InterBase Relation (v1.0) | 2 | |
| RELD | RELOAD serialization format | 2 | |
| RELS | 3D Manufacturing Format Relationships | 10 | |
| RELS | Open Office XML Relationships | 10 | |
| REM | BlackBarry encrypted REM format | 4 | |
| REMOTEMAP | Reason Remote Mapping | 12 | |
| REMOTEMAP | Reason Remote Mapping (UTF-8) | 3 | |
| REP | ACT! Report (v3.0) | 12 | |
| REP | Business Objects Report | 43 | |
| REP | Grand Theft Auto: San Andreas replay | 2 | |
| REP | Harvard Total Project Manager Report | 7 | |
| REP | Lotus Organizer Report | 39 | |
| REP | PC-File Report | 19 | |
| REP | Starcraft Replay | 13 | Kyosuke Aoki |
| REPL | Ultimate Stunts Replay | 2 | |
| REPLAY | Rocket League Replay | 101 | |
| REPLAY | Squad Replay | 8 | |
| REPLAY | Unreal Engine Replay (generic) | 23 | |
| REPO | yum Repository configuration | 7 | |
| REPORT/TXT | GENSCAN output results | 12 | |
| REPX | DevExpress Report layout (v1) | 21 | |
| REPX | DevExpress Report layout (v2) | 20 | |
| REPX | DevExpress Report layout (v2) (UTF-8) | 14 | |
| REPX | Simio Report template | 11 | |
| REQ | AskEnv Requester definition | 21 | |
| RES | .NET Framework Resource data | 5 | |
| RES | AESOP engine Resource data | 2 | |
| RES | Absolute Magic Resource data | 2 | |
| RES | Alchemy Mindworks Resource data | 4 | |
| RES | Allods 2 Rage Of Mages game data archive | 2 | |
| RES | Amaze Entertainment Resource data | 9 | |
| RES | ArtCraft Resource | 3 | |
| RES | Bink Texture | 2 | |
| RES | Borland Turbo Vision Resource | 2 | |
| RES | Depth Dwellers Resource/game data | 3 | |
| RES | Digimon Rumble Arena 2 game data archive | 6 | |
| RES | Dynamix SSM sound and music data container | 4 | |
| RES | Dynamix scene data container | 18 | |
| RES | Etherlords 2 game data archive | 3 | |
| RES | Godot Resource data | 8 | |
| RES | Haven Resource data | 2 | |
| RES | ITE Media Resouce game data archive | 2 | |
| RES | Klasik Resource data | 7 | |
| RES | Klasik text Resouce data | 7 | |
| RES | Looking Glass Resource data | 25 | |
| RES | M.A.X. game data archive | 5 | |
| RES | Microsoft Project 2.0-3.0 for DOS Resource | 3 | |
| RES | Microsoft Project 4.0 for DOS Resources | 3 | |
| RES/TRK | NASCAR Heat game data archive | 2 | |
| RES | Port Royale 4 game data | 2 | |
| RES | Project IGI Resource data | 5 | |
| RES | PureBasic Resident data (Win/Linux/OS X) | 32 | |
| RES | Road Wars Resource game data | 6 | |
| RES | SCream Engine resource data | 2 | |
| RES | SHELX output | 24 | |
| RES | SNNS result | 8 | |
| RES | SoftMax Resource | 2 | |
| RES | Stunt Island Resource (generic) | 35 | |
| RES/RSC/VGA | T-Resource game data container | 9 | |
| RES/LST/V2L/VGH | The Software Toolworks resources archive | 12 | |
| RES | Windows compiled resource | 21 | |
| RESMONCFG | Windows Resource Monitor Configuration | 6 | |
| RESOURCE | Game Studio Resource data | 4 | |
| RESOURCES | Doom Eternal Resource map | 4 | Masamune3210 |
| RESOURCES | Vivado Design Checkpoint Resource data | 18 | |
| RESX | Microsoft .NET XML Resource template | 25 | |
| RESX | Microsoft .NET XML Resource template (UTF-16 LE) | 5 | |
| RESX | Microsoft .NET XML Resource template (UTF-8) | 12 | |
| RET | RSView Enterprise Retentive Tags Database (v2) | 6 | |
| REU | REU Nuvie video | 105 | |
| REV | GEOS Revision | 463 | |
| REV/LIVECODE | MetaCard/Revolution/LiveCode stack (generic) | 15 | |
| REV | Revolution stack (v2.7) | 11 | |
| REV | Revolution stack (v5.5) | 3 | |
| REWASD | reWASD config | 18 | |
| REWASD | reWASD config (XML) | 13 | |
| REX | IGC VM/386 Relocatable Executable | 87 | |
| REX | ReCycled Audio Loop Export | 5 | |
| REZ | Escape Velocity Nova game data archive | 23 | |
| REZ | LithTech Resource data | 6 | |
| REZ | Medal Of Honor: Pacific Assult game data archive | 2 | |
| RF64/WAV | RF64 Multichannel Broadcast Wave format audio | 2 | |
| RFA | Revit Family Architecture project | 701 | |
| RFF | Build Engine RFF encrypted container | 2 | |
| RFI | Raw Flux disk Image | 2 | |
| RFL | Propellerhead Software Reason SoundBank | 8 | |
| RFLD | Ravenfield map | 6 | |
| RFLW | Edge Reflow data | 15 | |
| RFN/RFP/RFX | RoboForm saved data | 8 | |
| RFO | RoboForm cached data | 3 | |
| RFT | Autodesk Revit Family Template | 88 | Peter Glasl |
| RFT | Rush Font | 6 | |
| RFX/G3X | RealFlight data | 26 | |
| RG | Rosegarden composition (var.1) | 2 | |
| RG | Rosegarden composition (var.2) | 22 | |
| RGB | ColorViewSquash bitmap | 2 | |
| RGB | Intergraph Raster bitmap (Adaptive RLE RGB) | 1 | Joerg Jenderek |
| RGB | Silicon Graphics RGB bitmap | 16 | |
| RGD | Mesen Recent Game Data | 6 | |
| RGD | Raft saved Game Data | 4 | |
| RGE | EinScan 3D scan data | 2 | |
| RGE | R.A.G.E. Driver | 25 | |
| RGF | CADSTAR Report Generator (format 2) | 6 | |
| RGFX/RGX | IFF Retargetable Graphics bitmap | 16 | |
| RGH | ZZ ROUGH bitmap | 2 | |
| RGO | RepliGo virtual print | 5 | |
| RGP | RealArcade Game Package | 7 | |
| RGS | InstallShield Script for Windows Registry | 15 | |
| RGS | RealArcade Game Installer | 2 | |
| RGS | Rust Game engine 3D Scene | 29 | |
| RGSS2A | RPG Maker VX encrypted Archive (v2) | 3 | |
| RGSS3A | RPG Maker VX encrypted Archive (v3) | 2 | |
| RGSSAD | RPG Maker VX encrypted Archive (generic) | 6 | |
| RGT | Yamaha Registration snapshot | 45 | |
| RH | Rob Hubbard chiptune | 14 | |
| RHC | PerkinElmer Raw Hardcopy Chromatography (v3.50) | 2 | |
| RHL | Rathole compressed data | 11 | |
| RHO | Rob Hubbard ST module | 3 | |
| RIB | Renderman RIB | 7 | |
| RIDL | RAD Studio Active X RIDL data | 10 | |
| RIF | CyberLink Image Format | 4 | |
| RIF | LithTech Resource data (v1) | 6 | |
| RIF | MicroTik Router Information support output | 6 | |
| RIF | Painter Raster Image Format bitmap | 7 | |
| RIF | Rockwell ADPCM audio | 43 | |
| RIF | Zoetrope animation | 14 | |
| RIFF | Riff Raff module | 4 | |
| RIL | Image Librarian archive (generic) | 5 | |
| RIL | Image Librarian archive (v1.0) | 2 | |
| RIL | Image Librarian archive (v1.5) | 2 | |
| RIM | Atari ST PARX Read Image Module (SHI) | 27 | |
| RIM | Atari ST PARX Read Image Module (VDI) | 23 | |
| RIM | Atari ST PARX Read Image Module (VSH) | 5 | |
| RIM | Atari ST PARX Read Image Module (generic) | 71 | |
| RIM | EZ-DiskCopy PRO disk image | 3 | |
| RIM | Jade Empire game data archive | 2 | |
| RIMM | BlackBerry RIMM multimedia container | 4 | |
| RIP | RIPscript | 31 | |
| RIP | Rocky Interlace Picture bitmap | 8 | |
| RIR | Satori RIR scaled raster | 44 | |
| RIS | RIS citation format | 17 | |
| RIS | RIS citation format (UTF-8) | 6 | |
| RIVERS | AmiAtlas Rivers data | 2 | |
| RIX/SCX/SCI | ColoRIX bitmap | 25 | |
| RJP/SNG | RJP / Vectordean module | 103 | |
| RJS | Astra Report | 4 | |
| RJS | RealSystem Skin | 4 | |
| RK | My Little Pony Magic Princess / Ice Age model | 7004 | ego-lay_atman-bay |
| RK | REAPER license | 4 | |
| RK | RK compressed archive | 24 | Meigel |
| RK | RKEngine game data (generic) | 6 | |
| RK | Ron Klaren module | 11 | |
| RKA | RK Audio lossless compressed audio | 12 | |
| RKG | Mario Kart Wii ghost data | 2 | |
| RKI | RK Image compressed bitmap | 5 | |
| RKP | REKO cardset (PC-16) | 3 | |
| RKP | REKO cardset (PC-24, BMP) | 2 | |
| RKP | REKO cardset (PC-24, JPEG) | 3 | |
| RKP | REKO cardset (PC-8) | 6 | |
| RKP | RKP game package (v1.x) | 5 | |
| RKP | RemoteKeys profile | 18 | |
| RKT | RockSim Design | 49 | |
| RKU | Standalone RKIVE compressed data | 3 | |
| RL2 | AdLib Visual Composer 2 music | 15 | |
| RL2 | RL2 video | 15 | |
| RL6 | Norton pcAnywhere Remote session Log | 4 | |
| RLA | Alias Wavefront Raster bitmap | 21 | |
| RLB | Tsunami Media game data archive | 3 | |
| RLC | Radiant LoopCAD Project | 6 | |
| RLC | Xerox EDMICS-RLC bitmap (var.1) | 2 | |
| RLC | Xerox EDMICS-RLC bitmap (var.2) | 2 | |
| RLE | ADEX ChromaGraph bitmap (RLE compressed) | 2 | |
| RLE | Autodesk Screencast video (intermediate format) | 5 | Peter Glasl |
| RLE | CompuServe RLE bitmap (hi-res) | 51 | |
| RLE | CompuServe RLE bitmap (med-res) | 23 | |
| RLE | Golly Extended RLE | 8 | |
| RLE | Intergraph Raster bitmap (Run-Length Encoded, 1-bit) | 1 | Joerg Jenderek |
| RLE/BMP | Run Length Encoded bitmap | 19 | |
| RLE | Run Length Encoded bitmap (compression 1) | 180 | Joerg Jenderek |
| RLE/BMP | Run Length Encoded bitmap (compression 2) | 16 | Joerg Jenderek |
| RLE | Track Attack RLE compressed bitmaps/frames | 14 | |
| RLE | Track Attack RLE compressed cockpit | 3 | |
| RLE | Utah Raster Toolkit bitmap | 26 | |
| RLF | ArtCAM 3D Relief model | 15 | |
| RLF | Zork RLF video | 168 | |
| RLG | RegCleaner v4.3 Language File | 40 | .Cryorb |
| RLG | Roland SMF Player Language | 8 | |
| RLI | RealWorld Layered Image bitmap | 8 | |
| RLL | Microsoft Resource Library (x64) | 21 | Joerg Jenderek |
| RLL | Microsoft Resource Library (x86) | 44 | |
| RLM | Postal Realm data | 143 | |
| RLN | Alpha Four field rules | 17 | |
| RM/RA | Real Audio | 14 | |
| RM | Real Media stream | 21 | |
| RMD | R Markdown document | 30 | |
| RMF | RealMedia File container | 3 | |
| RMF | Rich Map Format | 18 | |
| RMF | Rich Music Format | 29 | |
| RMHD | RealMediaHD video | 6 | |
| RMI | RMI RIFF MIDI Music | 5 | |
| RML | Redline Markup Language | 3 | |
| RMP | Magellan Raster Map | 6 | |
| RMP | Real Metadata Package | 4 | |
| RMP | ReportMachine Prepared report | 2 | |
| RMSKIN | Rainmeter Skin | 3 | |
| RMT | RASTER Music Tracker module | 40 | |
| RMTL | Rhino 3D Material | 4 | |
| RMVB | RealVideo Variable Bit Rate | 8 | |
| RMX | RealMedia Secure clip | 7 | |
| RNC | RNC / PRO-PACK archive | 11 | |
| RNC | Rob Northen Compression (type 1) | 2 | |
| RNC | Rob Northen Compression (type 2) | 2 | |
| RND | AutoCAD Autoshade rendering slide | 5 | Paresh Modi |
| RNG | RELAX NG | 14 | |
| RNQS | Pokemon Randomization Quick Settings | 8 | |
| RNS | Propellerheads Reason Song file | 2 | |
| RNS | Renoise module (old) | 38 | |
| RNT | Richnote backup (LG Android) | 8 | |
| ROC | SpaceCAD rocket model | 7 | |
| ROCKSPEC | LuaRocks Package Specification | 7 | |
| RODL | RemObjects Definition Language | 5 | |
| RODX | Nethar Ancestry genealogical XML | 11 | |
| RODZ | Nethar Ancestry genealogical archive | 4 | |
| ROF | ROFF 3D animation | 2 | |
| ROI | IONTOF SurfaceLab TOF-SIMS Region of Interest | 6 | |
| ROI | Olympus OIF ROI | 9 | |
| ROL | AdLib Visual Composer music | 110 | |
| ROLF | Relux Open Luminaire Format | 9 | |
| ROM/BIN | BIOS ROM Extension (IA-32 PCI) | 45 | Joerg Jenderek |
| ROM/BIN | BIOS ROM Extension (IA-32 PNP) | 40 | Joerg Jenderek |
| ROM/BIN | BIOS ROM Extension (IA-32) | 26 | Joerg Jenderek |
| ROM | Cloanto Amiga OS encrypted ROM | 14 | |
| ROM | CompROM compressed ROM image | 5 | |
| ROM/BIN | Intel serial flash ROM (ICH) | 397 | Joerg Jenderek |
| ROM | Killing Floor Map | 18 | |
| ROM | MSX ROM Image | 22 | |
| ROM | MSX2 ROM Image | 12 | |
| ROM/F5 | Nvidia Graphics Interface ROM | 29 | |
| ROM | SpartaDOS X binary image | 11 | |
| ROM | Uxn program (with metadata) | 2 | |
| ROOT | ROOT format | 2 | |
| ROQ | Id Software RoQ video | 10 | |
| ROR | ROR Structured Feed | 9 | |
| ROS | ReachOut Script | 5 | |
| ROSE | Rosegarden musical notation (RV21) | 8 | |
| ROT | Home World 2 - ROT graphics | 12 | |
| ROTACT | ROT Object 3D Action | 4 | |
| ROTOBJ | ROT Object 3D | 4 | |
| ROUTE | AmiAtlas Routes data | 3 | |
| ROX | Roxanne animation | 11 | |
| ROX | Roxio project | 18 | |
| ROXIO | Roxio Easy Media Creator Project | 8 | Tyler Thorsted |
| ROZ | aSc Timetables timetable | 54 | |
| RP | Student Writing Center Report | 2 | |
| RP-LIB | RetroPlatform Library | 3 | |
| RP-SKIN/RP_SKIN | RetroPlatform Skin | 9 | |
| RP2 | RetroPlatform Player archive (old) | 10 | |
| RP9 | RetroPlatform Player archive | 153 | |
| RPA | Ren'Py Archive (v1) | 2 | |
| RPA | Ren'Py Archive (v2) | 2 | |
| RPA | Ren'Py Archive (v3) | 7 | Anton Valdez |
| RPA | Ren'Py Archive (v4) | 2 | |
| RPACK | Dying Light game data archive | 2 | |
| RPACK | Techland game data archive | 7 | |
| RPAD | RealProducer Profile | 40 | |
| RPAK | Apex Legends game data archive | 633 | That1MiningGuy |
| RPAK | Respawn Entertainment game data archive (generic) | 634 | |
| RPAK | Titanfall 2 game data archive | 5 | |
| RPC | ACT! Report (v2.0) | 2 | |
| RPC | RAR Password Cracker project | 2 | |
| RPD | RapidFile Data | 4 | |
| RPF | ASTRA Report Profile | 2 | |
| RPF | RAGE Package Format (GTA IV Audio Midnight Club: LA) | 2 | |
| RPF | RAGE Package Format (GTA IV) | 2 | |
| RPF | RAGE Package Format (GTA V) | 2 | |
| RPF | RAGE Package Format (Max Payne 3) | 2 | |
| RPF | RAGE Package Format (Red Dead Redemption) | 2 | |
| RPF | RAGE Package Format (Table Tennis) | 2 | |
| RPF | RAGE Package Format (generic) | 5 | |
| RPG | OHRRPGCE game | 49 | |
| RPGMVO | RPG Maker MV encrypted Ogg Vorbis audio | 12 | |
| RPI | ZX Spin Render Plugin | 38 | |
| RPJ | CA Realizer Project (v3.0) | 4 | |
| RPJF | RealProducer Job File | 10 | |
| RPK | Rule of Rose game data archive | 2 | |
| RPL | ARMovie video | 7 | |
| RPL | Deluxe Ski Jump 2 Replay | 39 | |
| RPL | Farallon Replica document | 3 | |
| RPL | Microsoft Golf 2.0 Replay | 13 | |
| RPL | NASCAR Racing 3 Replay | 29 | |
| RPM | RPM Package (generic) | 28 | |
| RPM/SPM | RPM Package (v3.0 source) | 164 | Joerg Jenderek |
| RPM | RPM Package source (src.rpm) | 20 | |
| RPMSG | Restricted-Permission Message | 5 | |
| RPP | REAPER Project | 24 | |
| RPROJ | RStudio Project | 8 | |
| RPS | DevExpress Report | 12 | |
| RPS | Propellerhead Software Reason Song | 6 | |
| RPSD | RealProducer Server Destination | 4 | |
| RPT | Central Point Anti-Virus search report | 10 | |
| RPT | Crystal Reports output file (Report) | 50 | |
| RPT | Eureka/Mercury Report | 5 | |
| RPT | Family Origins Report (v5.x) | 4 | |
| RPT | Kaspersky Anti-Virus reports | 359 | xoxmodav |
| RPT | Navratil Software System Information Report | 8 | |
| RPT | Poswiz! Report (v1.0) | 35 | |
| RPT | ProvideX Report | 8 | |
| RPT | ReportSmith report (ver 3.x) | 14 | |
| RPT | WinAsks Player Report (v2.00) | 10 | |
| RPX | ActiveReports Report | 10 | |
| RPX | ActiveReports Report (UTF-8) | 306 | |
| RPY | NASCAR Racing 4 Replay | 24 | |
| RPYC/RPYMC | Ren'Py Compiled script/module | 7 | |
| RPZ | ReproZip (GZipped) | 16 | |
| RPZ | ReproZip (TAR) | 30 | |
| RQS | MIDIAN Request Setup | 7 | |
| RR | RR compressed data archive | 13 | |
| RRA | Windows Installer temp data | 10 | |
| RRD | RRD4J Round Robin Database | 4 | |
| RRD | Round-Robin Database | 9 | |
| RRES | rres resource package | 2 | |
| RRES | rres resource package (old) | 2 | |
| RRH | BlackBerry resource | 5 | |
| RRM | The Lost Files of Sherlock Holmes Resource data | 50 | |
| RRUFF/TXT | RRUFF spectral data | 2299 | |
| RS | RS compressed archive | 7 | Label |
| RS/SND | Steve sound format | 91 | |
| RS5 | Miasmata game data | 2 | |
| RSB | Zuma's Revenge game data archive | 3 | |
| RSC | After Dark for DOS Resource data | 2 | |
| RSC | MicroStation Symbology Resources | 3 | |
| RSC | MikroTik RouterOS configuration | 15 | |
| RSC/RSI | PAI Virtuoso Resource data (generic) | 4 | |
| RSC | SuperScape Resource | 3 | |
| RSC | Symbian OS resource data | 10 | |
| RSC | Turbo Out Run game data | 3 | |
| RSC32/RSC/RSE | RSC32 recovery info | 5 | |
| RSCOLLECTION | RetroShare Collection | 4 | |
| RSCT | REINER SCT transfer file | 21 | Joerg Jenderek |
| RSD | PlayStation RSD 3D model info (gen) | 2 | |
| RSD | PlayStation RSD 3D model info (v3.0) | 2 | |
| RSDK | Taxman's Retro Engine SDK data | 2 | |
| RSDOC | DesignSpark Mechanical 3D Document | 34 | |
| RSE | Secret Mission scenario data | 180 | |
| RSECC | rscode encoded | 4 | |
| RSF | Nintendo 3DS RSF descriptive data | 12 | |
| RSF | Roland Stroke Font | 4 | |
| RSG | Drakan: Order Of The Flame Saved Game | 82 | .Cryorb |
| RSG | Exanima save game | 12 | |
| RSH | Warhammer 40K textures | 4 | |
| RSJ | FreePascal JSON Resource Strings format (v1) | 16 | |
| RSL | RSLogix Ladder Logic program | 34 | |
| RSLCD | AIDA64 Remote Sensors LCD config | 7 | |
| RSLIB | RobotStudio library | 4 | |
| RSM | Ragnarok Online Model | 2 | |
| RSM | ResourceMaster project (v3.x) | 7 | |
| RSM | Resume | 11 | |
| RSM | WinWay Resume (v4.0) | 17 | |
| RSM2 | Ragnarok Online Model (v2) | 3 | |
| RSN | RAR packaged SPC soundtrack | 17 | |
| RSND/IFF | IFF RSND audio | 7 | |
| RSO | LEGO NXT brick audio | 10 | |
| RSP | RSLogix 5 Project | 44 | |
| RSP | Rapport Script | 2 | |
| RSP | Repeat Signage Presentation | 19 | |
| RSR | Fractal Design Painter Resource | 6 | |
| RSRC | BeOS Resource data | 75 | |
| RSS | Emu80 RK snapshot | 3 | |
| RSS | Rockwell Logix 500 SLC-5 Software | 22 | |
| RSSTN | ABB RobotStudio Station | 4 | |
| RST | BRIEF session info | 4 | |
| RST | SharpShooter Reports Report Template | 8 | |
| RSVO | Sparse Voxel Octree (binary) (v1) | 4 | |
| RSY | FLEXIT Multishot Survey Raw Data file | 4 | |
| RT | RealTime subtitles | 16 | |
| RTAB | RandyTab guitar tablature | 7 | |
| RTB | RivaTuner data base Build | 26 | |
| RTB | SKick Relocation/patch Table | 19 | |
| RTBW | Syzygy tablebase win/draw/loss | 9 | |
| RTBZ | Syzygy tablebase distance-to-zero | 14 | |
| RTC | Office Live Meeting Connection | 8 | |
| RTC | Rise of the Triad level | 2 | |
| RTD | RTPatch Documentation | 11 | |
| RTD | RTPatch Documentation (ASCII-7) | 6 | |
| RTD | RagTime Document | 12 | |
| RTD | RealTime Device | 5 | |
| RTE | Autodesk Revit Template | 49 | Peter Glasl |
| RTE | Fugawi route format | 8 | |
| RTE | RTE encoded file | 2 | |
| RTF | Real Time File | 194 | |
| RTF | Rich Text Format | 68 | |
| RTI | Okino plugin Run Time Information | 14 | |
| RTI | RASTER Music Tracker Instrument | 35 | |
| RTL | Clarion RunTime Library | 18 | | NEW! |
| RTL | HP Raster Transfer Language | 30 | |
| RTL | Norton Utilities Library | 9 | |
| RTL | Rise of the Triad Level | 2 | |
| RTM | BIS Binarized Rtm animation | 2 | |
| RTM | BIS Rtm animation | 2 | |
| RTM | Real Tracker module | 8 | |
| RTON | PopCap Games data | 5 | |
| RTP | GROMACS Residue Topology | 16 | |
| RTP | GROMACS Residue Topology (with rem) | 9 | |
| RTP | RTPDump format | 4 | |
| RTP | RTPatch update/diff data | 39 | |
| RTPL | Relux Template | 9 | |
| RTPL | Relux Template (UTF-16 LE) | 7 | |
| RTREE | TatukGIS Rectangle Tree spatial index | 7 | |
| RTS | RealTime Section/pattern | 7 | |
| RTS | Roytal TS remote connection | 4 | |
| RTST_PAK | Recursion Real-Time Stat Tracker Package | 10 | |
| RTTEX/RTFONT | RTPACK game data format (uncomp.) | 27 | |
| RTTEX/RTFONT | RTPACK game data format (zlib comp.) | 35 | |
| RTW | RealTime Workspace | 8 | |
| RTZ | RedTitan Zip | 4 | |
| RUL | ANSI/AAMA grade Rule table | 6 | |
| RUL | DRC Rules export | 8 | |
| RUL | TETRHEX Rule (v3) | 3 | |
| RULE | Golly Rule | 52 | |
| RULESET | Visual Studio Code Analysis Rule Set | 3 | |
| RULESET | Visual Studio Code Analysis Rule Set (UTF-8) | 8 | |
| RUN | 3D Construction Kit game Runner | 4 | |
| RUN | Amiga AC/BASIC compiled executable | 18 | |
| RUN | AppImage Portable Linux App (old) | 33 | |
| RUN | Makeself SFX compressed archive (v2.x) | 19 | |
| RUN | Rune map | 21 | |
| RUNSETTINGS | Visual Studio unit test configuration | 7 | |
| RUNSETTINGS | Visual Studio unit test configuration (UTF-8) | 3 | |
| RUP | NINJA 2.0 Patch | 2 | |
| RUS | Navitel 1.1 Map | 5 | |
| RUX | Relux Custom User Interface Package | 5 | |
| RVC | TNTmips Project (Windows) | 293 | Christian Wolkersdorfer |
| RVD | Raster-Vector Hybrid Drawing | 18 | Peter Glasl |
| RVD | Rend386 video driver | 7 | |
| RVF | RichView Format (Unicode) | 47 | Kieran O'Donnell |
| RVIZ | RViz workspace | 17 | |
| RVIZ | RViz workspace (with rem) | 5 | |
| RVL | Muvee project | 11 | |
| RVM | Retro Virtual Machine | 6 | |
| RVN | Riven saved game | 49 | |
| RVP | RVX 3D Engine game data | 2 | |
| RVPROJ | RPG Maker VX Project | 5 | |
| RVPROJ2 | RPG Maker VX Ace Project | 6 | |
| RVR | Roland Virtual Sonics samples library | 3 | |
| RVT | Autodesk Revit Project | 60 | Peter Glasl |
| RVZ | Nintendo compressed disk image | 20 | |
| RW2/RAW | Panasonic RAW image | 21 | |
| RW3 | Regressi Win data | 16 | |
| RW4 | RenderWare 4 model (PC) | 198 | |
| RW4 | RenderWare 4 model (Xbox 360) | 16 | |
| RWD | TimeGate Studios game data archive | 2 | |
| RWE | RightWriter settings (v5 Win) | 2 | |
| RWL | Leica RAW image | 11 | |
| RWO | RightWriter document (v5 Win) | 2 | |
| RWS | Aspell dictionary | 37 | Joerg Jenderek |
| RWSAVE | Rusted Warfare Saved game | 4 | |
| RWSD | RWSD Audio Stream | 2 | |
| RWT | ReadWriteThink data | 8 | |
| RWT | RightWriter Style (v1 Win) | 2 | |
| RWT | RightWriter Style (v5 Win) | 9 | |
| RWX | RenderWare 3d model | 10 | |
| RWX | RenderWare 3d model (with rem) | 66 | |
| RWZ | Rawzor compressed raw image | 5 | |
| RX | Photogenics REXX script | 28 | |
| RX | TVPaint REXX script | 34 | |
| RX1 | Ports of Call RDK Point Of Contact Curve eXport | 146 | |
| RX2 | EA RX2 Image | 2 | |
| RX2/REX | REX2 audio sample loop | 10 | |
| RX3 | Ports of Call office asset | 14 | |
| RXD | Borland Reflex Database | 6 | |
| RXDATA/RVDATA2 | RPG Maker data | 227 | |
| RXDOC | iZotope RX document | 8 | Tyler Thorsted |
| RXE | LEGO Mindstorms NXT Executable | 2 | |
| RXF | Recipe Exchange Format | 13 | |
| RXF | Resco encrypted file | 9 | |
| RXM | GisRX GPS Navigator map | 7 | |
| RXN | MDL Reaction format | 21 | |
| RXO | Receiver Independent Exchange Format | 23 | |
| RXS | Borland Reflex Screen driver | 8 | |
| RXT | X-Stitch Designer Gold Template | 102 | |
| RZ | rzip compressed archive | 2 | |
| RZX | File Crypt encrypted | 104 | Red Zion |
| RZX | RamSoft's ZX Spectrum Replay | 2 | |
