State tax exemption on intra state supplies of specified used motor vehicles: margin based taxation applies, subject to tax credit exclusion. State tax exemption applies to intra state supplies of specified old and used motor vehicles, taxed only on the supplier's margin at reduced rates for listed categories; vehicle specifications follow the Motor Vehicles Act. Margin for depreciated assets is sale consideration less depreciated value, and for others is selling price less purchase price, with negative margins ignored. Exemption is unavailable if the supplier has availed input tax credit, CENVAT, VAT or other tax credits. The notification is effective from 25 January 2018.