List IV contains important information for the mariner in relation to
radiocommunications, including the GMDSS (Global Maritime Distress
and Safety System). Detailed information such as the frequencies for
transmitting and receiving, in addition to geographical coordinates,
is provided for maritime coast radio stations, including those assuming
watch-keeping using digital selective calling (DSC) techniques and
radiotelephony. List IV also supplies details of additional services such as
medical advice, navigational and meteorological warnings, MSI (Maritime
Safety Information), AIS (Automatic Identification System), meteorological
bulletins and radio time signals, along with the hours of service and
operational frequencies, information on port stations, pilot stations, coast
Earth stations, VTS stations, contact information of RCC (Rescue
Coordination Centers), SAR agencies, Navarea coordinators and AtoNs
(AIS Aids to Navigation).

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.