Additional Customs duty practice clarified: past non-levy means recovery of that additional duty is not required for affected imports. Clarification that, where an established administrative practice resulted in non-levy of the additional duty of Customs under the Customs Tariff Act on specified goods during a prior period, the Government directs that the additional duty which would have been payable but for that practice shall not be required to be paid for imports on which the duty was not levied during that period, aligning recovery with the prevailing practice.