U.S. note 16(j)
(j) Headings 9903.82.20 and 9903.82.21 apply to derivative steel articles provided for in subdivision (c)(xi) of this note that are eligible for special tariff treatment under the United States-Mexico-Canada Agreement. Heading 9903.82.20 applies to the non-U.S. content of such derivative steel articles and to U.S. content that exceeds 40 percent of the value of such derivative steel articles. Heading 9903.82.21 applies to the U.S. content that does not exceed 40 percent of the value of such derivative steel articles. For the purposes of this note, U.S. content refers to the value of the article attributable to parts produced in the United States. Importers of such derivative steel articles shall identify the amount of U.S. content in each article imported into the United States. The non-U.S. content of the article shall be calculated by subtracting the value of the U.S. content in the article from the total value of the article. Any importer entering an article covered by this subdivision shall provide any information that may be required, and in such form, as is deemed necessary by CBP in order to permit the administration of this heading.