Rules of Origin ensure preferential tariff treatment subject to verification by a designated Verification Authority and customs definitions. Rules set the terminology for administering preferential tariff treatment: preferential rate of duty, preferential tariff treatment, Rules of Origin, and tariff notification; undefined terms take their statutory meanings. Verification is defined as checking the genuineness of a proof of origin under the applicable Rules of Origin, and a Verification Authority in the exporting or origin country is designated to respond to verification requests. A substitution clarifies that the instrument verified is termed a proof of origin.