S.C. Code Ann. § 24-21-1220: Construction and application.

(A)(1) Nothing in this article prevents the enforcement of another law of a compacting state that is consistent with this compact.

(2) All compacting states' laws conflicting with this compact are superseded to the extent of the conflict.

(B)(1) All lawful actions of the Interstate Commission, including all rules and bylaws promulgated by the Interstate Commission, are binding upon the compacting states.

(2) All agreements between the Interstate Commission and the compacting states are binding in accordance with their terms.

(3) Upon the request of a party to a conflict over meaning or interpretation of Interstate Commission actions, and upon a majority vote of the compacting states, the Interstate Commission may issue advisory opinions regarding the meaning or interpretation.

(4) In the event a provision of this compact exceeds the constitutional limits imposed on the legislature of a compacting state, the obligations, duties, powers, or jurisdiction sought to be conferred by the provision upon the Interstate Commission must be ineffective and the obligations, duties, powers, or jurisdiction must remain in the compacting state and must be exercised by the agency to which such obligations, duties, powers, or jurisdiction are delegated by law in effect at the time this compact becomes effective.