| Code | Description |
| AP | AUTOPILOT: Magnetic |
| DE | DECCA Navigation |
| EC | Electronic Chart Display & Information System (ECDIS) |
| ER | Engine room monitoring system |
| GP | Global Positioning System (GPS) |
| HN | HEADING SENSORS: Gyro, Non-North Seeking |
| II | Integrated Instrumentation |
| IN | Integrated Navigation |
| LA | LORAN: Loran A |
| LC | LORAN: Loran C |
| OM | OMEGA Navigation System |
| P | Proprietary Code |
| SN | Eletronic positioning system, other/general |
| SS | Sounder, scanning |
| TR | TRANSIT Navigation System |
| VM | VELOCITY SENSORS: Speed log , water, magnetic |
| VW | VELOCITY SENSORS: Speed log, water, mechanical |
| YX | Transducer |
| ZA | TIMEKEEPERS, TIME/DATE: Atomic clock |
| ZC | TIMEKEEPERS, TIME/DATE: Chronometer |
|