Preferential tariff treatment claims require importer diligence, origin verification, and compliance with trade agreement rules. Procedure for claiming preferential rate of duty under a trade agreement requires the importer to declare originating status, possess sufficient origin-related information, furnish it in the prescribed manner, and exercise reasonable care. Submission of a proof of origin does not absolve the importer, and the proper officer may seek further information, suspend preferential tariff treatment, require security or differential duty deposit, inform the Issuing Authority, and disallow the claim where information is not furnished or is unsatisfactory.