GMDSS: Element 7

1. A Transmitter identity (numerals from 1 to 26 identifying transmitting station within the NAVAREA).
2. B Subject indicator (single letter from A to Z indicating the type of message).
3. C The Answerback of the receiving station has not been entered in the NAVTEX receiver.
4. D Only messages having a serial number 00 are rejected.

Tip: press A-D to answer