Circular
A1. The IMO and the international regulatory frameworkDefinition
Non-binding IMO output such as MSC.1/Circ. or MEPC.1/Circ. used for guidance and clarifications.
An IMO circular is a non-binding output used for guidance, interpretation, and dissemination of information. Committee circulars carry prefixes such as MSC.1/Circ. or MEPC.1/Circ. with a running number. Unlike resolutions, circulars do not adopt mandatory instruments; they clarify how existing requirements apply, distribute unified interpretations, or notify parties of agreed practices.
Source: IMO documentation conventions