U.S. note 37(b)
(b) The rates of duty set forth in heading 9903.76.01 apply to all imported softwood timber and lumber products, as specified in subdivision (a) to this note, that are classified under the provisions of the HTSUS listed in this subdivision: 4403.11.00 4403.21.01 4403.22.01 4403.23.01 4403.24.01 4403.25.01 4403.26.01 4403.99.01 4406.11.00 4406.91.00 4407.11.00 4407.12.00 4407.13.00 4407.14.00 4407.19.00