ad valorem equivalent
(4) The term “ad valorem equivalent” means the ad valorem equivalent of a specific rate or, in the case of a combination of rates including a specific rate, the sum of the ad valorem equivalent of the specific rate and of the ad valorem rate. The ad valorem equivalent shall be determined by the President on the basis of the value of imports of the article concerned during the most recent representative period. In determining the value of imports, the President shall utilize, to the maximum extent practicable, the standards of valuation contained in section 1401a or 1402 of this title (as in effect before the effective date of the amendments made by title II of the Trade Agreements Act of 1979) or in section 1401a of this title (as in effect on the effective date of such title II amendments) whichever is applicable to the article concerned during such representative period.