| Abbreviation | Definition |
|---|---|
| RUS | Russian text |
| RVC | Raster Vector Converted format |
| RVF | Raster Vector Format |
| RVW | Review |
| RWS | Resource Workshop Symbol file ( Borland C++) |
| RWX | Criterion RenderWare Script |
| RWX | MEME Shape File |
| RWZ | Outlook Rules Wizard files |
| RXD | Reflex 1 Datafile |
| RZC | RaZor Command |
| RZF | RaZor File |
| RZO | RaZor Operation |
| S | Assembly language source code file |
| S | Modula-3 Foreign assembly Source file |
| S$$ | Temporary sort file (Sprint) |
| S1K | S1000 Simnet Format |
| S3I | Sample file (Digiplayer - ST3) |
| S3M | Scream Tracker III 16-channel Music file |
| SAF | Spatial Archive Interchange Format |
| SAIF | Spatial Archive Interchange Format |