Artikel 18

1. Any Contracting Party may, when depositing its instrument of ratification, approval or accession, or at any later date, by declaration addressed to the depositary Government, extend this Convention to any territory or territories for whose international relations it is responsible. The provisions of this Convention shall enter into force for such territory or territories on the ninetieth day after receipt of such declaration, or on the date on which the Convention enters into force in accordance with paragraph 1 of Article 16, whichever is the later.
2. Any declaration made in pursuance of the preceding paragraph may, in respect of any territory mentioned in such declaration, be withdrawn according to the procedure laid down in Article 19.