| rtax | RTA Gateway Exported Configuration |
| rto | Rumba File Transfer Profile |
| rub | JQuery Rules Data |
| ruleset | Visual Studio Code Analysis Rule Set |
| rvs | Lattice Reveal Analyzer Settings |
| s2c | Spike2 Configuration Data |
| s2cx | Spike2 v7 Configuration Data |
| samrc | SAM Default Parameters Data |
| sbs | Substance Designer Substance Package |
| sbsprs | Substance Designer Presets Data |
| scacfg | SuperCard Application Configuration |
| scheme | Sothink Logo Maker Color Scheme |
| scpcfg | SuperCard Project Configuration |
| scpresets | Snap Converter Presets Data |
| sde | ArcSDE Connection File |
| sdg | OpenOffice.org Configuration File |
| sdv | OpenOffice.org Configuration File |
| seb | Safe Exam Browser Configuration |
| security | Java JRE Security Settings Data |
| set | General Settings File |
| set | SmartCAM Connection Settings File |
| settings | Configuration File |
| sfpreset | Sony Preset Manager Preset |
| sfs | Sibelius Configuration File |
| sgc | Secure SnapGear Router Configuration |
| shi | Simple Help Editor Settings |
| shortcut | Asutype Shortcut Data |
| sif | Windows NT Setup Information File |
| skt | Lightwave 3D Skytracer Settings |
| sldreg | SolidWorks Saved Settings |
| slip | Embarcadero License Configuration |
| sll | SpectraLayers Pro Layout Settings |
| smartftp | SmartFTP Configuration Data |
| smn | SetEdit Menu Configuration |
| smprf | System Mechanic Windows Startup Profile |