Supply of goods or services expanded; states barred from taxing out-of-state or import/export supplies, Parliament sets principles. The amendment replaces references to 'sale or purchase of goods' with 'supply of goods or of services or both', prohibiting State laws from imposing tax on such supplies when they occur outside the State or in the course of import into or export out of India, authorising Parliament to formulate principles to determine when a supply falls within those prohibitions, and omitting the former clause that imposed express parliamentary restrictions on certain State taxes.