| spc | Microsoft Software Publisher Certificate |
| spc | Thermo Scientific SPC File |
| spcmd | Stereoscopic Player Commands Data |
| spcolor | Microsoft SharePoint Color Palette Data |
| spd | Form Z Suspended Rendering FIle |
| spd | SpecTRM Specification |
| spd | SPSD/M Database |
| spd | Windows Server Security Policy Database |
| spda | Surveyor PDA Detector Data |
| spdata | Microsoft SharePoint Project Data |
| spdb | iGO Primo SpeedCam Database |
| spdnv | Spreadtrum NV Backup |
| spe | SPSS Extension |
| speccy | Speccy Snapshot Data |
| spef | Standard Parasitic Exchange Format |
| spentry | Spartan Entry Database |
| spex | SPEX Data |
| spexp | Substance Painter Export Preset Data |
| spf | SQR Portable Format |
| spfs | Spider File Storage |
| spg | SG TCP Optimizer Backup |
| sph | Altair FEKO TICRA Spherical Data |
| sph | MikuMikuDance Sphere Multiplied Map |
| sph | Ribbons Sphere Definition |
| sphere | Geomview Sphere Data |
| spin | Apple Mac OS X Console Spin Report |
| spinput | Spartan Spinput Format File |
| spk | SPARKvue v1.0 Data |
| spklab | SPARKvue Lab Project |
| spl | Abacom sPlan Components Database |
| spl | AkAbak Simulation Data |
| spl | Windows Spool Data |
| spl | WinView/400 Report Data |
| spl7 | Abacom sPlan 7 Circuit Diagram |
| splan | SPSS Statistics Simulation Plan |