Drawback rate fixation: inputwise documentation and certified verification required to link imported inputs, wastage and by product claims to duty proof. Procedure requires three linked statements: DBK I lists inputwise raw materials/components with quantities, wastage, by products and certificates by the exporter and an independent Chartered Engineer/Cost Accountant confirming use, non substitution of imported inputs and reasonableness of wastage; DBK II records direct imports/locally obtained foreign materials with bill of entry, assessable value, tariff and duty status with accountant certification; DBK IIA details imported input stocks as of the commencement date with bills of entry and certification.