U.S. note 2(aa)(vi)
(vi) As provided in heading 9903.03.07, the additional duty imposed by heading 9903.03.01 shall not apply to any products of Canada entered free of duty under the United States-Mexico-Canada Agreement, including any treatment set forth in subchapter XXIII of chapter 98 and subchapter XXII of chapter 99 of the HTSUS, but regardless of whether a product is entered under a provision for which the rate of duty “S or S+” appears in the “Special” sub-column.