| sk2 | ACD/ChemSketch Drawing Document |
| skchr | SketchChair Design |
| skd | Autodesk AutoSketch Drawing |
| sketch | Sketch Drawing Document |
| skg | Skrooge Document |
| skin | Help and Manual Viewer Template |
| skk | SmartSketch Drawing |
| skl | XLIFF Skeleton File |
| skt | WinSketch Pro Diagram |
| sktz | Sony Sketch Drawing |
| skv | Semicolon Separated Values |
| skw | SideKick Write Document |
| sky | Microsoft Multiplan SYLK Spreadsheet |
| sl1 | Articulate Storyline Document |
| sla | Scribus Document |
| slb | Autodesk AutoCAD Slide Library |
| sld | Autodesk AutoCAD Slide Library |
| sld3 | Microsoft PowerPoint 3 for Mac Slide Document |
| sld8 | Microsoft PowerPoint 98 for Mac Slide Document |
| sldbndtbt | SolidWorks Bend Table Template |
| sldbomtbt | SolidWorks Bill of Materials Template |
| slddot | SolidWorks Sheet Template |
| slddrt | SolidWorks Sheet Document |
| slddrw | SolidWorks Drawing Document |
| slddwg | SolidWorks 2D Vector Drawing |
| sldfvt | SolidWorks Favorite |
| sldm | Microsoft PowerPoint 2007 Slide |
| slds | Microsoft PowerPoint 2 for Mac Slide Document |
| sldtbt | SolidWorks General Table Template |
| sldx | Microsoft PowerPoint 2007 Slide |
| sldxml | SolidWorks 3DEXPERIENCE XML Document |
| sls3 | Microsoft Excel 3 for Mac Template |
| sls4 | Microsoft Excel 4 for Mac Template |
| sls5 | Microsoft Excel 5 for Mac Template |
| sls8 | Microsoft Excel 98 for Mac Template |
| slt | Senlab Template |
| slt | Shark LT Drawing |
| slvs | SolveSpace Document |
| sm | Samna Word Text Document |
| sm | SMath Studio Document |
| smdf | Surface Magic Design |
| smf | OpenOffice Math Formula |
| smf | StarOffice StarMath Formula |
| smht | Sealed MHT Document |
| smlx | Steel Markup Language Document |
| smm | Ami Pro Macro |
| smp | SLIM‐DataManager Workbook |
| smpl | Megahedron 3D Object |
| smst | Adobe Soundbooth Score Toolkit Document |
| smus | Simple MUsical Score Document |
| smw | SLIM‐Metrics Workbook |
| smz | SMath Studio Compressed Document |
| snapdoc | Ashampoo Snap Document |
| sng | WorshipCenter Pro Song Data |
| snp | Microsoft Access Report SnapShot |
| soap | Simple Object Access Protocol Message |
| sp | LTspice Netlist Data |
| spartan | Spartan Document |
| spd | SoftPlan Drawing Document |
| spd | WinLens Lens Design |
| spdf | Sealed PDF Document |
| spect | Spectacles Document |
| spk | Bright Spark Document |
| spl | FutureSplash Animator Document |
| spn | Sealed PNG Image |
| spot | Sealed PowerPoint Template |
| spotm | Sealed PowerPoint 2007 Template without Macros |
| spotx | Sealed PowerPoint 2007 Template |
| sppt | Sealed PowerPoint Presentation |
| spptm | Sealed PowerPoint 2007 Presentation without Macros |
| spptx | Sealed PowerPoint 2007 Presentation |
| spr | Brother Powernote Spreadsheet |
| spr | Psion Series 3 Spreadsheet |
| sprz | Sprintometer Document |
| sps | Altova StyleVision SPS Document |
| spub | Swift Publisher Document |
| spw | SigmaPlot Worksheet |
| spw | SLIM-MasterPlan Workbook |
| spx | Pfaff Stitch Creator Pattern |
| srb | Corel WordPerfect Scrap Book |
| srk | SharkCAD Drawing |
| srtf | Sealed Rich Text Format Document |
| sru | Search/Retrieve via URL Response Format Data |
| ssiw | Corel WordPerfect for Mac 4 Document |
| ssm | Samsung S Memo Data |
| ssn | Samsung S Note File |
| ssvg | Sealed SVG Document |
| sswf | Sealed SWF Document |
| st1 | DigiTitle Master Subtitle |
| stb | AutoCAD Named Plot Style Table |
| stc | OpenOffice Calc Template |
| std | Expressit SE CD/DVD Label Template |
| std | PROMT Translator Document |
| std | StarOffice Drawing Template |
| std | SureThing CD Labeler Document |
| step | ISO 10303 STEP Document |
| sth | KG-Chart Design Data |
| sti | Sealed TIFF Image |
| sti | StarOffice Impress Template |
| stk | Writer's Cafe StoryLines Document |
| stl | StereoLithography Data |
| stla | ASCII StereoLithography Data |
| stml | Sealed HTML Document |
| story | Storyist Document |
| 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 |
| stw | StarOffice Writer Template |
| stx | Roxio Express Labeler Document |
| stxt | Sealed Text Document |
| sty | Corel Ventura Publisher Style Sheet |
| sty | Harvard Graphics Style |
| sty | LaTeX Style Definition |
| sty | NewsMaker Story Document |
| suck | SiteSucker Website Data |
| sud | WISCO Word Power Sudoku Puzzle |
| suml | Simple UML Diagram |
| svd | 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 |
| swe | 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 |
| 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 | StarOffice Math Document |
| sxml | Sealed XML Document |
| sxw | OpenOffice Writer Document |
| sxw | StarOffice Writer v6 Document |
| sy3 | Harvard Graphics Symbol |
| syv | Outline 4D Template |
| sza | HiCAD Drawing |
| szn | HiCAD Old Drawing |
| szx | HiCAD SZX Drawing |
| t2 | Textease 2000 Document |
| t2d | TouchDraw Document |
| t2l | TouchDraw Library |
| t2t | Sonata CAD Model |
| t2t | Txt2tags Text Document |
| t4g | TommySoftware CAD Drawing |
| t65 | Adobe Pagemaker 6.5 Template |
| tab | ASCII Guitar Tab |
| tbl | Adobe Pagemaker Table |
| tbscene | Marmoset Toolbag 3D Scene |
| tbt | TabIt Document |
| tbt | Toon Boom Studio Template |
| tbx | Turbo Cross Design |
| tc2 | TurboCAD Mac Drawing |
| tc6 | Calc602 Spreadsheet Document |
| tcd | Tenado CAD Drawing |
| tcd | TurboCAD Mac Deluxe Drawing |
| tcd | TurboCalc Spreadsheet Document |
| tceltx | Celtx Template |
| tcm | TurboCAD Mac Drawing |
| tcp | TurboCAD Mac Pro Drawing |
| tcr | MotionMagix Creative Suite Published Data |
| tct | TurboCAD Template |
| tcw | TurboCAD Drawing |
| tcx | TurboCAD Drawing (ASCII) |
| tdd | Tables Direct Template |
| tdg | Tree Diagram Generator Document |
| tdoc | Tabula Document |
| ted | MotionMagix Editable Document Template |
| tee | TeeChart Chart Document |
| tef | TablEdit Tablature |
| teg | TeXgraph Source Code |
| tem | HiTi Photo Desiree v1 Template |
| template | Apple Pages Template |
| ten | TeeChart Chart Template |
| terx | RoadEng Terrain Design Document |
| tex | LaTeX Document |
| texi | GNU Texinfo Document |
| textbundle | Highland TextBundle Document |
| textclipping | Mac OS X Text Clipping |
| tfm | FormTool Gold Form Document |
| tfrd | Tape Format Requirements Document |
| tft | Text Formatter Plus Formatting Data |
| tg | TuxGuitar Document |
| tgf | Trivial Graph Format |
| thing | MakerBot Thing Document |
| thl | Total 3D Home Design |
| thml | Theological Markup Language Document |
| thmx | Microsoft Office 2007 Theme |
| tii | TI Interactive Workbook |
| tilt | Tilt Brush Sketch |
| tip | Tru-Designer Presentation |
| tkl | Takeoff Live Document |
| tldr | tldraw Drawing |
| tlg | Intuit QuickBooks Transaction Log |
| tlq | Art Explosion T-Shirt Factory Deluxe Document |
| tm | TeXmacs Document |
| tm3 | TreeMap Document |
| tm5 | Adobe Pagemaker 5.0 Template |
| tm6 | Adobe Pagemaker 6.0 Template |
| tmbak | TextMaker Document Backup |
| tmd | TextMaker Document |
| tmd | Tomahawk Gold Document |
| tmdx | TextMaker 2018 Document |
| tmr | Apimac Timer Document |
| tmv | TextMaker Document Template |
| tmvt | LexisNexis TimeMap Template |
| tmvx | TextMaker 2018 Template |
| tns | TI-Nspire Document |
| tnsp | TI-Nspire PublishView Document |
| tnv | Bitware Fax Document |
| toc | Adobe FrameMaker TOC |
| top | Adesso Cyberpad Handwriting Document |
| top | Topocad Drawing Document |
| top | TopSolid Design Document |
| topviw | TopSolid Viewer Document |
| totalslayout | Totals Invoice Layout File |
| tow | TOWER Model |
| tp | TinkerPlots Document |
| tp3 | Harvard Graphics 3.0 Template |
| tpd | Treepad v7 Database |
| tpl | ArchiCAD Project Template |
| tpl | Canvas Template |
| tpl | DataCAD Template Document |
| tpt | ThumbsPlus Template |
| tpt | Treepad Template |
| tpt | Tru-Designer Presentation Template |
| tpz | Treepad Zipped Database |
| trelby | Trelby Document |
| tsb | 3dMD 3D Image |
| tsce | TextShield Compressed RTF File |
| tse | Light Map Maker Scene |
| tst | Corel WordPerfect 5 Printer Test Document |
| tst | ExamView Test File |
| tsv | Tab-Separated Values Data |
| ttax | Newton Dictate Transcription Document |