| stp | Catia Document |
| stpl | Sevilla Template |
| stplz | Sevilla Compressed Template |
| stpxz | XZ Compressed STEP Document |
| stpz | Catia Compressed STEP Document |
| struct | Microsoft XPS Document Structure Data |
| sttpl | Samsung Theme Designer Showcase |
| studio | Silhouette Studio Document |
| studio3 | Silhouette Studio Document |
| Silhouette Studio SD Card Document |
| stw | StarOffice Writer Template |
| stx | Roxio Express Labeler Document |
| stxt | Sealed Text Document |
| sty | Corel Ventura Publisher Style Sheet |
| Harvard Graphics Style |
| LaTeX Style Definition |
| NewsMaker Story Document |
| suck | SiteSucker Website Data |
| sud | WISCO Word Power Sudoku Puzzle |
| suml | Simple UML Diagram |
| svd | Microsoft Word Autosave Document |
| SolidView Design |
| svf | Simple Vector Format Document |
| svr | Superscape VR Compressed World |
| swar | SolidWorks Auto-recovery Document |
| swdoc | SymWriter 2 Document |
| swe | SendaWin Etiquetas Label |
| Sweater Wizard Document |
| swg | SWAG Pascal Snippets |
| swgr | ClarisWorks 3 Drawing |
| swp | Borland Sprint Document Backup |
| swss | ClarisWorks 3 Spreadsheet |
| swx | OpenOffice.org 1.0 Text Document |
| sxc | OpenOffice Calc Document |
| sxd | OpenOffice Draw Document |
| sxe | ProfiCAD Schematics Diagram |
| sxg | OpenOffice.org Writer Global Document |
| sxi | OpenOffice Impress Document |
| sxl | Sealed Excel Document |
| sxls | Sealed Excel Document |
| sxlsm | Sealed Excel 2007 Document without Macros |
| sxlsx | Sealed Excel 2007 Document |
| sxlt | Sealed Excel Template |
| sxltm | Sealed Excel 2007 Template without Macros |
| sxltx | Sealed Excel 2007 Template |
| sxm | Sealed XML Document |
| StarOffice Math Document |
| sxml | Sealed XML Document |
| sxw | OpenOffice Writer Document |
| StarOffice Writer v6 Document |
| sy3 | Harvard Graphics Symbol |
| syv | Outline 4D Template |
| syw | Harvard Graphics Symbol |
| sza | HiCAD Drawing |
| szn | HiCAD Old Drawing |
| szx | HiCAD SZX Drawing |
| t09 | Pfaff Embroidery Document |
| Pfaff Stitch Creator Pattern |
| t2 | Textease 2000 Document |
| t2d | TouchDraw Document |
| t2l | TouchDraw Library |
| t2t | Sonata CAD Model |
| Txt2tags Text Document |
| t4g | TommySoftware CAD Drawing |
| t65 | Adobe Pagemaker 6.5 Template |
| tab | ASCII Guitar Tab |
| tabula-doc | Tabula Document |
| tbl | Adobe Pagemaker Table |
| tbscene | Marmoset Toolbag 3D Scene |
| tbt | TabIt Document |
| Toon Boom Studio Template |
| tbx | Turbo Cross Design |
| tc2 | TurboCAD Mac Drawing |
| tc3 | TurboCAD Mac Drawing |
| tc6 | Calc602 Spreadsheet Document |
| tcd | Tenado CAD Drawing |
| TurboCAD Mac Deluxe Drawing |
| TurboCalc Spreadsheet Document |
| tceltx | Celtx Template |
| tcm | TurboCAD Mac Drawing |
