Tax Rate Changes: provisional immediate effect declared; central excise and customs rates and classifications revised across multiple sectors. Specified clauses of the Finance Bill, 2012 have been declared to take provisional effect from the midnight of 16th/17th March, 2012 so that revised customs and central excise duty rates, notifications and valuation rules operate immediately pending enactment. The Circular summarises rate increases and restructurings (standard and merit excise rates, RSP/section 4A valuation for certain goods, tobacco slab adjustments, jewellery tariff-value levy), consolidation of exemption notifications, selective reliefs, amendments to Cenvat rules and procedural changes, and corresponding Customs Tariff and legislative amendments affecting classification, cognizability, and recovery mechanisms.