Refund of unutilised input tax credit: amended formula and specified goods restriction apply prospectively to later-filed applications. An amendment to the refund calculation formula for unutilised input tax credit due to inverted duty structure applies prospectively to applications filed on or after its effective date, with pre amendment applications governed by the earlier formula; a separate notification barring refunds for specified goods likewise applies prospectively to applications filed on or after its effective date and does not affect earlier filings.