https://www.taxtmi.com/caselaws?id=72118 Exemption notifications operate prospectively unless retrospective effect is expressly provided or the notification is demonstrably clarificatory. Accordingly, cushion compound captively consumed before the exemption date remained subject to central excise duty; a written demand identifying the relevant period and amount could satisfy Rule 9(2), particularly where manufacture and captive use were not fully disclosed. For periods in which the department knew of captive consumption, the demand was time-barred under Rule 10. Duty also required reassessment because applicable rates varied and assessable value needed recomputation. The earlier-period liability therefore survived only for fresh quantification and valuation. en-us Thu, 18 Jul 1985 00:00:00 +0530 Thu, 12 May 2011 11:55:49 +0530 TaxTMI RSS Generator https://www.taxtmi.com/caselaws?id=72118 Exemption notifications operate prospectively unless retrospective effect is expressly provided or the notification is demonstrably clarificatory. Accordingly, cushion compound captively consumed before the exemption date remained subject to central excise duty; a written demand identifying the relevant period and amount could satisfy Rule 9(2), particularly where manufacture and captive use were not fully disclosed. For periods in which the department knew of captive consumption, the demand was time-barred under Rule 10. Duty also required reassessment because applicable rates varied and assessable value needed recomputation. The earlier-period liability therefore survived only for fresh quantification and valuation. Case-Laws Central Excise Thu, 18 Jul 1985 00:00:00 +0530 https://www.taxtmi.com/caselaws?id=72118