Inter State sale exemption: no central tax on supplies to registered dealers for authorised special economic zone units, subject to conditions. Amendments to section 8 permit charging the lower of the four per cent turnover rate or the appropriate State sales tax rate, treat goods generally exempt under State law as nil for calculation purposes while deeming dealers liable for such calculations, restrict what counts as a general exemption, include telecommunications within certain supplies, condition State permissions on fulfilment of requirements, and create an exemption from central sales tax for inter State sales to registered dealers supplying authorised units in a special economic zone subject to certificate classes and a prescribed declaration.