| sqm | Microsoft Message Queuing Data |
| sqp | Sonique Audio Search Query Result Data |
| sqs | SQL Script Sequences |
| squ | LabWindows Test Sequence |
| sqv | VisionWorks LS Image Sequence Data |
| sqw | Horace Data |
| sqy | Xaira Saved Query |
| sr1 | SIR Schema Rectype and Variable Specs Data |
| sr2 | SIR Schema Textual Specs Data |
| sr3 | SIR Index and Data |
| sr4 | SIR Procedure Definitions Data |
| sr5 | SIR Database Journal Data |
| sr6 | SIR Alternate Index |
| sr7 | SAS Item Storage |
| sr8 | RECOIL Data |
| sra | Sequence Read Archive |
| srd | Summary Record Database |
| srec | Motorola S-record Data |
| srf | BrainVoyager QX Surface Data |
| srfl | SurfLogger Log |
| srfmap | Terragen Surface Map Data |
| srg | Ketron Single Registration |
| srh | BMC Remedy AR System Server Saved Search |
| srl | SmartWare Resource Library |
| srl | ASwin Shared Database |
| srm | SNES Save State File |
| srn | SCIRun Network File |
| sro | ATIS SR Output File |
| srp | MotionTracking Object Search Parameters Data |
| srr | Xilinx ISE Synplicity Report |
| srs | Microsoft Outlook Send/Receive Settings |
| srx | SPARQL Query Results XML |
| ss | Ribbons Secondary Structure |
| ss1 | Cygnus MK Data Logger Single Record |
| ss3 | SKM Power Tools PPE Table Information |