(a) To claim the in-quota rate of duty on sugar-containing products of a participating country, the United States importer must make a declaration to the United States Customs Service, in the form and manner determined by the United States Customs Service, that a valid export certificate is in effect with respect to those sugar-containing products.

(b) To be valid, an export certificate shall:

(1) Be issued by or under the supervision of the government of the participating country;

(2) Specify the name of the party to whom the certificate is issued, the product description and quantity, shipment date, and the quota year for which the export certificate is in effect;

(3) Have a distinct and uniquely identifiable number; and

(4) Be used in the quota year for which it is in effect.