The NVU shall contain or may contain the following information:
- The format of the message
- The protocol used (may differ from the model or in which application it is used)
- The country code and the remaining 6 digits of the MMSI code (in some countries Call Sign is used)
- The number of EPIRBs on board
- If analogue transmission at 121.5 MHz is present
- The activation mode (automatic or manual)
- If there is an internal tracking system (GPS).