Drawback definition clarified: refund of duty, tax or cess on importation is claimable on re-export, with procedural wording revised. The amendment substitutes the definition of drawback to mean the refund of duty, tax or cess referred to in the Customs Tariff Act and paid on importation, claimable under the Customs Act, and removes the phrases 'or Principal Commissioner or Commissioner of Customs and Central Excise' from the proviso to rule 5(1), thereby narrowing the specified office-holder references.