| sito | Stuffit Translator Data |
| sitv | StuffIt Viewer Data |
| siw | ANSYS SIwave Data |
| sj | Google Science Journal Data |
| sjd | Scrapbook Factory Journal Data |
| sjf | SCAPS SAM JobFile Format |
| sjt | Sirovision 3D Image |
| sjx | Seljax Estimating and 3D Design Data |
| sk | Safari History Index |
| ska | PGP Secret Keyring Data |
| skba | Autodesk SketchBook Pro Animation File |
| skc | SideKick Card |
| skcard | Borland Sidekick Card File |
| skd | SSEYO Koan Design |
| WinOrbit Data |
| skel | Geomview OOGL Objects SKEL Data |
| sketchpad | Sketchpad Drawing Data |
| skf | Sage Accounting Data |
| SkinCrafter Skin Data |
| skim | Skim Notes File |
| skin | InstallShield Compiled Skin Data |
| skindex | Apple Mail Index Data |
| skl | Autodesk Maya Skeleton Works Data |
| WinLIFT Skin |
| sklib | Skatter Library Data |
| skm | SSEYO Koan Data |
| skn | Avant Browser Skin Data |
| Symbian OS Skin Data |
| Windows Automotive Skin |
| skp | COREX Orthographic Transcription with Signal Linking Data |
| Sage Accounting Print Data |
| SSEYO Koan Play Data |
| skpkmz | SketchUp Data |
| skr | Gaussian Scratch File |
| PGP Private Keyring File |
| ScriptIt Data |
| sks | Show.kit Template |
| skt | SSEYO Koan Design |
| SSEYO Koan Play Data |
| sku | TomTom for R-Link Map Update |
| sky | Adobe Acrobat Language Resource |
| skypechatstyle | Skype Chat Style Data |
| skypeemoticonset | Skype Emoticon Pack |
| sl | RenderMan Shader Source |
| Sam Spade Startup Script |
| sl2 | Lowrance Sonar Log v2 File |
| SQLite 2.0 Database |
| sl3 | SQLite 3 Database |
| slb | Multiframe Sections Library |
| PSpice Symbols Library |
| slbk | Smart Launcher Home Screen Backup |
| slc | SLiCe Format Data |
| sld | Corel Paint Shop Pro Styled Line Data |
| NEPLAN Graphic Export Data |
| XnView Slideshow |
| sldasm | SolidWorks Assembly Document |
| sldblk | SolidWorks Blocks File |
| sldbombt | SolidWorks BOM Template |
| sldclr | SolidWorks Color Palette Data |
| sldcts | SolidWorks Template Database |
| sldd | Simulink Data Dictionary |
| slddc | Simulink Data Dictionary Cache |
| sldedb | SolidWorks Database |
| sldftp | SolidWorks Form Tool File |
| sldgtolfvt | SolidWorks Geometric Tolerance Style |
| sldgtolstl | SolidWorks Geometric Tolerance Symbols Style |
| sldholtbt | SolidWorks Hole Table Template |
| sldlfp | SolidWorks Library Features File |
| sldmat | SolidWorks Material Database |
| sldnotestl | SolidWorks Notes Style |
| sldpr | SolidWorks Part Document |
| sldprt | SolidWorks Part Document |
| sldrevtbt | SolidWorks Revision Table Template |
| sldsffvt | SolidWorks Surface Finish Style |
| sldsfstl | SolidWorks Surface Finish Symbols Style |
| sldstd | SolidWorks Drafting Standards Data |
| sldstl | SolidWorks Dimensions Style |
| sldweldfvt | SolidWorks Weld Style |
| sldweldstl | SolidWorks Weld Symbols Style |
| sldwldtbt | SolidWorks Weldment Cutlist Template |
