| stv | SofTV Author File |
| stx | SAS XPORT Transport File |
| styk | Stykz Stick Figure |
| stykz | Stykz Animation File |
| styles | Steam Client GUI Resources Data |
| styx | ChordWizard Songtrix Style Data |
| su2 | I2P Software Update File |
| su3 | I2P Software Update File |
| sua | Tim Newport-Peace Special Use Airspace Format File |
| sub | WRAP SIMD Sub-monthly Time Step Simulation Data |
| subs | AvantGo Subscription Data |
| substvar | TIBCO BusinessWorks Substitution Variable Data |
| suc | Softrans Hello Engines! Data |
| sud | Super Project Data |
| sud | I2P Software Update File |
| suf | ZENworks Endpoint Security Management Import File |
| sui | StarSplatter User Interface |
| suite | Theme Manager Data |
| suj | Stacker Unlimited Job |
| sup | Super Project Definition File |
| sup | ADS40 Socet Support Data |
| sup | SOCSIM Supervisory File |
| supf | Egothor Similar Unit Pairs Data |
| sur | Topocad Survey Data |
| surf | V_sim Surface Data |
| sus | SAP Transactionware GM POS Xpress Suspended Data |
| sut | ELITEpro Setup Tables Data |
| suu | Dell System Update Utility Archive |
| suv | SpriteUV2 Data |
| sv$ | Autodesk AutoCAD Automatic Save File |
| sv2 | SAS View |
| sv2 | SAS Stat Studio Metadata |
| sv2i | Symantec System Index |
| sv7 | SAS View |
| svap | SolidWorks Visualize Appearance Library |