Artikel 29

Any State may, at the time of signature, ratification or accession, declare that the present Convention shall extend to all the territories for the international relations of which it is responsible, or to one or more of them. Such a declaration shall take effect on the date of entry into force of the Convention for the State concerned.
At any time thereafter, such extensions shall be notified to the Ministry of Foreign Affairs of the Netherlands.
The extension will have effect only as regards the relations with such Contracting States as will have declared their acceptance of the extensions. Such a declaration shall be deposited at the Ministry of Foreign Affairs of the Netherlands; this Ministry shall forward, through diplomatic channels, a certified copy to each of the Contracting States.
The extension will take effect in each case sixty days after the deposit of the declaration of acceptance.