CENVAT credit on common inputs clarified: credit disallowed when compliance conditions fail; board to review earlier recovery. Allowance of CENVAT credit is barred where a manufacturer fails to maintain separate accounts or comply with the prescribed alternative mechanism; rule 6(1) disallows credit on inputs used for exempted goods and precludes the subsequent taking-and-reversing of credit if the conditions are not met. The Board will further examine recovery under the alternative compliance route for earlier periods and will communicate its decision.