State property exemption from Union taxation permits Parliament to authorise taxes on State-run trade or business. The property and income of a State are immune from Union taxation, but Parliament may by law authorise taxes on any trade or business carried on by or for a State, related operations, property used for such trade or business, or income arising therefrom; Parliament may also declare classes of trade or business to be incidental to ordinary governmental functions, to which such authorisation does not apply.