| 1. | .ov | Database file (Revelation-DOS) |
| 2. | .ov1 | Overlay file (part of program to be loaded when needed) |
| 3. | .ov2 | Overlay file (part of program to be loaded when needed) |
| 4. | .ovd | Datafile (ObjectVision) |
| 5. | .ovg | Converted graphic file (ObjectVision) |
| 6. | .ovl | Overlay file (part of program to be loaded when needed) |
| 7. | .ovr | Overlay file (part of program to be loaded when needed) |