The ITU Radiocommunication Assembly, considering that Recommendation ITU-R M.493-5, 9 5.2 has recommended that the X digit of the DSC address always be the figure O and is reserved for future use; that a need has arisen for multiple DSC radios to be installed on a single vessel; that various administrations only issue one MMSI according to Appendix 43 of the Radio Regulations to any vessel.
ITU-R M.1080 SPANISH-1994 Referenced Document
ITU-R M.493-5 Digital Selective-Calling System for Use in the Maritime Mobile Service - Section 8B - Maritime Mobile Service; Telegraphy and Related Subjects
ITU-R M.1080 SPANISH-1994 history
1994ITU-R M.1080 SPANISH-1994 DIGITAL SELECTIVE CALLING SYSTEM ENHANCEMENT FOR MULTIPLE EQUIPMENT INSTALLATIONS