| schakal | SCHAKAL Chemical Modeller Input file |
| schdoc | Altium Designer Schematic File |
| schemas | GNOME GConf Schema Definition |
| schk | SortSite Site Data |
| schlib | Altium Designer Schematic Library |
| scml | Spriter Data |
| scmt | GXS Application Integrator XML Constraint |
| scn | AutoDesk Softimage Scene |
| sco | Microsoft IIS Schema Backup |
| scp | SCP-ECG Data |
| scpb | Survivorship Care Plan Builder Data |
| scprt | Surfcam 3D Format Data |
| scrate | Serato DJ Smart Crate Data |
| scs | Siemens Mobil Phone Color Skin |
| scs | StuffIt Saved File List |
| scssc | Sass Compiled Data |
| sctid | RSA SecurID Software Certficate Import Data |
| scvd | µVision System Component Viewer Description |
| scy | ReaGeniX License Data |
| sd | STK Satellite Database Main File |
| sd2 | SAS Data Set |
| sd3 | Hy-Tek Meet Manager SDIF Data |
| sd4 | Smart Diary Suite 4 Database |
| sd5 | Agilent E6474A Recorded Measurement Data |
| sd7 | SAS Data Set |
| sd7 | Daktronics Venus 7000 Schedule Data |
| sda | SoftMax Pro Data |
| sdac | CoCreate OneSpace Assembly Container Data |
| sdam | Source Data Model Data |
| sdax | SoftMax Pro Data |
| sdb2 | Shure Wireless Workbench Database |
| sdbs | BLAST+ Personal Database |
| sdbx | Autodesk AutoCAD Civil 3D Survey Database |
| sdbz | Symantec EP Support Tool Information File |
| sdcp | SimpleDiagrams Color Palette |