| Abbreviation | Definition |
|---|---|
| RMCF | Right Move Chess Foundation |
| RXB | Rook takes Bishop |
| RXN | Rook takes Knight |
| RXP | Rook takes Pawn |
| RXQ | Rook takes Queen |
| RXR | Rook takes Rook |
| SACA | Southern Arizona Chess Association |
| SCC | Success Chess School, Newark, California |
| SCCU | Southern Counties Chess Union |
| SCF | Frank Samford, Jr., Chess Foundation |
| SCID | Shane's Chess Information Database |
| SCP | Simple Chess Program |
| SDCA | San Diego Chess Academy |
| SDCA | South Dakota Chess Association |
| SECF | Sioux Empire Chess Foundation, Sioux Falls, South Dakota |
| SPOC | Selective Pruning Optimization Chess |
| TCA | Tennessee Chess Association |
| TCA | Texas Chess Association |
| TCCL | Twin Cities Chess League |
| TCEC | Top Chess Engine Championship |