U.S. note 20(ff)
(ff) For purposes of heading 9903.88.27, the additional duties imposed by heading 9903.88.15 shall not apply to entries under subheadings 2106.90.52, 2106.90.54, 6103.22.00, 6103.23.00, 6103.29.05, 6103.29.10, 6103.29.20, 6104.22.00, 6104.23.00, 6104.29.05, 6104.29.10, 6203.22.30, 6203.29.10, 6203.29.15, 6203.29.20, 6203.29.30, 6204.21.00, 6204.22.30, 6204.23.00, 6204.29.20, 8215.10.00, 9005.90.40, 9005.90.80, 9110.11.00, 9110.90.20, and 9608.50.00, if such entries are subject to an applied rate of duty under such enumerated subheadings that is derived from another subheading that is subject to the additional duties imposed by heading 9903.88.03 or 9903.88.09.