47 C.F.R. § 80.87 Cooperative use of frequency assignments.
Title 47 - Telecommunication
Each radio channel is available for use on a shared basis only and is not available for the exclusive use of any one station or station licensee. Station licensees must cooperate in the use of their respective frequency assignments in order to minimize interference and obtain the most effective use of the authorized radio channels.
Title 47: Telecommunication
PART 80—STATIONS IN THE MARITIME SERVICES
Subpart C—Operating Requirements and Procedures
Operating Procedures—General
§ 80.87 Cooperative use of frequency assignments.

