is a service publication prepared and issued, once a year, by the International Telecommunication Union (ITU), in accordance with provision no. 20.8 of the Radio Regulations (RR). As stipulated in Appendix 16 to the RR, this List shall be provided to all ship stations for which a Global Maritime Distress and Safety System (GMDSS) installation is required by international agreement. New edition released annually in March or April.