Customs duty schedule update: Revised ad valorem and specific rates substituted across virtually all tariff subheadings, including exemptions. The Schedule substitutes entries in column (4) (and where specified column (5)) of the First Schedule to the Customs Tariff Act for many chapters and listed sub headings, replacing prior duties with prescribed ad valorem percentages, specific per unit duties and combined 'percentage or specific amount, whichever is higher' formulations, and in limited cases specifying 'Free.' The instrument identifies exact sub heading numbers and the precise substituted entries for duty assessment.