Artikel 21

1. Any State may, at the time of signature or when depositing its instrument of ratification, acceptance, approval or accession, specify the territory or territories to which this Convention shall apply.
2. Any Contracting Party may, when depositing its instrument of ratification, acceptance, approval or accession or at any later date, by declaration addressed to the Secretary General of the Council of Europe, extend the application of this Convention to any other territory specified in the declaration and for whose international relations it is responsible or on whose behalf it is authorised to give undertakings.
3. Any declaration made under the preceding paragraph may, in respect of any territory mentioned in such declaration, be withdrawn by notification addressed to the Secretary General. Such withdrawal shall become effective on the first day of the month following the expiry of a period of six months after the date of receipt of the notification by the Secretary General.