Reversal of cenvat credit requires manufacturers to reverse credit or pay duty on written off inputs, WIP, or finished goods. Where the value of any input on which cenvat credit has been taken is fully written off, Rule 3(5B) requires reversal of that credit. Goods that have been manufactured attract excise duty at manufacture and the manufacturer must pay duty or reverse credit where duty is remitted under the remission mechanism; Rule 3(5C) mandates reversal when duty is remitted. WIP that amounts to manufacture receives the same treatment as finished goods; WIP not amounting to manufacture is treated as input for reversal purposes.