The Convention shall apply also to any identical or substantially similar taxes which are imposed after the date of signature of the Convention in addition to, or in place of, the existing taxes. The competent authorities of the Contracting States shall notify each other of any significant changes which have been made in their respective taxation laws or other laws affecting their obligations under the Convention, and of any official published material concerning the application of the Convention, including explanations, regulations, rulings, or judicial decisions.