In no case shall the provisions of Articles 28 and 29 be construed so as to impose on a Contracting State the obligation:
- a)to carry out administrative measures at variance with the laws and administrative practice of that or of the other Contracting State;
- b)to supply information which is not obtainable under the laws or in the normal course of the administration of that or of the other Contracting State;
- c)to supply information which would disclose any trade, business, industrial, commercial or professional secret or trade process, or information, the disclosure of which would be contrary to public policy (ordre public).