| Class | Sources in the RBS | Sources with optical coordinates |
|---|---|---|
| AGN | 900 | 899 |
| Clusters | 294 | 294 |
| Cataclysmic Variables | 50 | 49 |
| Galaxies | 9 | 9 |
| Compact Groups | 3 | 3 |
| Magellanic Cloud Sources | 49 | 30 |
| Stars | 759 | 756 |
| X-ray Binaries | 3 | 2 |
| Ultra Luminous X-Ray Sources | 1 | 1 |
| Unclassified Sources | 4 | 0 |
| Summary | 2072 | 2043 |