| skindex | Apple Mail Index Data |
| skl | Autodesk Maya Skeleton Works Data |
| skn | Windows Automotive Skin |
| skr | PGP Private Keyring File |
| skr | Gaussian Scratch File |
| skypechatstyle | Skype Chat Style Data |
| skypeemoticonset | Skype Emoticon Pack |
| sl | RenderMan Shader Source |
| sl2 | Lowrance Sonar Log v2 File |
| sl3 | SQLite 3 Database |
| slb | Multiframe Sections Library |
| slc | SLiCe Format Data |
| sldasm | SolidWorks Assembly Document |
| sldblk | SolidWorks Blocks File |
| sldbombt | SolidWorks BOM Template |
| sldclr | SolidWorks Color Palette Data |
| sldedb | SolidWorks Database |
| sldftp | SolidWorks Form Tool File |
| sldlfp | SolidWorks Library Features File |
| sldmat | SolidWorks Material Database |
| sldprt | SolidWorks Part Document |
| sldrevtbt | SolidWorks Revision Table Template |
| sldsffvt | SolidWorks Surface Finish Style |
| sldstd | SolidWorks Drafting Standards Data |
| sldwldtbt | SolidWorks Weldment Cutlist Template |
| slg | Autodesk AutoCAD Status Log |
| slg | Symantec Endpoint Protection Database Log |
| slg | Lowrance Sonar Log File |
| sli | EOS PSW SLI Data |
| slib | LightTools SLIB Data |
