Power to waive excise recovery when a widespread practice causes non-levy or short-levy, subject to refund rules. Central Government may notify that excise duty need not be recovered where a generally prevalent practice led to non-levy or short-levy of duty on goods liable to duty or to a higher duty; such notification exempts the whole duty or excess duty that would otherwise have been payable. Duty already paid, or paid in excess, is to be processed under the established refund mechanism, and refund claims must be made to the Assistant Commissioner or Deputy Commissioner of Central Excise in the prescribed form within six months of the notification.