The Secretary of the Treasury of Puerto Rico may, as a condition to recognize any exemption provided by § 1921 of this title, require from any person claiming such exemption a certificate issued by an official or representative duly authorized by the United States Government, showing that the goods, articles, and commodities mentioned in said certificate are included in the tax exemption granted in § 1921 of this title.\nHistory —May 13, 1948, No. 188, p. 522, § 2.
Puerto Rico Legal Code