The Realm can by way of legislation, frame general principles concerning the validity and collection of taxes levied by the Lands to protect important interests of society and prevent:—
(1) Prejudice to the revenues or commercial relations of the Realm.
(2) Levies on public communications or institutions if excessive or such as to interfere with communication.
(3) Where, in the course of traffic between the different Federal States or provinces, commodities entering a certain State suffer financial disabilities as compared with the same class of commodity manufactured in such State.
(4) In order to exclude export premiums or to safeguard important social interests.
Article 12.
As long as, and in so far as, the Realm makes no use of its rights of legislation, the Lands retain the right of legislating. This does not apply to legislation which belongs to the Realm exclusively.
The Government of the Realm has the right of veto against any legislation of the Lands which affects the provisions of Number 13 of Article 7, in so far as the interests of the whole community of the Realm are thereby affected.
Article 13.
Law of the Realm prevails against law of the Lands.