What are the message types in Navtex?

Message types in Navtex- The nature of each NAVTEX communication is classified using the message category.

Message types in Navtex are: ‘D’ (search and rescue), ‘A’ and ‘L’ (navigational warnings), and ‘E,’ ‘B,’ and ‘C’  (meteorological warnings).

To know more, please check Navtex