All Ships covered by the I.S.P.S. code must have an “International Ship Security Certificate”.
The Flag state authority issues this certificate after verifying compliance and approval of the Ship Security Plan.
This procedure can be delegated to a “Recognised Security Organisation” (RSO) such as a classification society. Recognised Security Organisation is commonly abbreviated as RSO
This certificate will be checked during port-state controls.
The Flag State authority will periodically audit the ship’s security arrangements, in order to determine the vessel’s continuing qualification for renewal of the “International Ship Security certificate”.