Artikel 17

1. Any State Member of the Council and any State Member of the United Nations or its specialised agencies may become a Contracting Party to this Convention:
(a) by signing it without reservation of ratification;
(b) by depositing an instrument of ratification after signing it subject to ratification; or
(c) by acceding to it.
2. This Convention shall be open until 30th June 1971, for signature at the Headquarters of the Council in Brussels, by the States referred to in paragraph 1 of this Article. Thereafter, it shall be open for their accession.
3. Any State, not being a Member of the Organizations referred to in paragraph 1 of this Article, to which an invitation to that effect has been addressed by the Secretary General of the Council at the request of the Contracting Parties, may become a Contracting Party to this Convention by acceding thereto after its entry into force.
4. The instruments of ratification or accession shall be deposited with the Secretary General of the Council.