| 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 |
| skd | WinOrbit Data |
| skel | Geomview OOGL Objects SKEL Data |
| sketchpad | Sketchpad Drawing Data |
| skf | Sage Accounting Data |
| skf | SkinCrafter Skin Data |
| skim | Skim Notes File |
| skin | InstallShield Compiled Skin Data |
| skindex | Apple Mail Index Data |
| skl | Autodesk Maya Skeleton Works Data |
| skl | WinLIFT Skin |
| sklib | Skatter Library Data |
| skm | SSEYO Koan Data |
| skn | Avant Browser Skin Data |
| skn | Symbian OS Skin Data |
| skn | Windows Automotive Skin |
| skp | COREX Orthographic Transcription with Signal Linking Data |
| skp | Sage Accounting Print Data |
| skp | SSEYO Koan Play Data |
| skpkmz | SketchUp Data |
| skr | Gaussian Scratch File |
| skr | PGP Private Keyring File |
| skr | ScriptIt Data |
| sks | Show.kit Template |
| skt | SSEYO Koan Design |
| skt | SSEYO Koan Play Data |
| sku | TomTom for R-Link Map Update |
| sky | Adobe Acrobat Language Resource |
