confirmation or accession, the extent of their competence with respect to matters governed by the present Convention. Subsequently, they shall inform the depositary of any substantial modification in the extent of their competence. 2. References to “States Parties” in the present Convention shall apply to such organizations within the limits of their competence. 3. For the purposes of article 45, paragraph 1, and article 47, paragraphs 2 and 3, of the present Convention, any instrument deposited by a regional integration organization shall not be counted. 4. Regional integration organizations, in matters within their competence, may exercise their right to vote in the Conference of States Parties, with a number of votes equal to the number of their member States that are Parties to the present Convention. Such an organization shall not exercise its right to vote if any of its member States exercises its right, and vice versa. Article 45 Entry into force 1. The present Convention shall enter into force on the thirtieth day after the deposit of the twentieth instrument of ratification or accession. 2. For each State or regional integration organization ratifying, formally confirming or acceding to the present Convention after the deposit of the twentieth such instrument, the Convention shall enter into force on the thirtieth day after the deposit of its own such instrument. Article 46 Reservations 1. Reservations incompatible with the object and purpose of the present Convention shall not be permitted. 2. Reservations may be withdrawn at any time. Article 47 Amendments 1. Any State Party may propose an amendment to the present Convention and submit it to the Secretary-General of the United Nations. The SecretaryGeneral shall communicate any proposed amendments to States Parties, with a request to be notified whether they favour a conference of States Parties for the purpose of considering and deciding upon the proposals. In the event that, within four months from the date of such communication, at least one third of – 30 –