Article 21 Signature and Ratification 1. This Protocol shall be signed and ratified by the Member States in accordance with their respective Constitutional procedures. 2. The instruments of ratification or accession shall be deposited with the Secretary General of the OAU. Article 22 Entry into Force This Protocol shall enter into force thirty (30) days after the deposit of the instruments of ratification by a simple majority of the Member States. Article 23 Accession 1. Any Member State may notify the Secretary General of its intention to accede to this Protocol after its entry into force. The Secretary General shall, upon receipt of such notification, transmit copies thereof to all Member States. 2. For any Member State acceding to this Protocol, the Protocol shall come into force on the date of the deposit of its instrument of accession. Article 24 Amendment or Revision of the Protocol 1. This Protocol may be amended or revised by the decision of a two-thirds majority of the Assembly. 2. Any Member State party to this Protocol or the Pan-African Parliament may propose, in writing to the Secretary General, any amendment or revision of the Protocol. 3. The Secretary General shall notify the proposal to all Member States at least thirty (30) days before the meeting of the Assembly, which is to consider the proposal. 4. The Secretary General shall request the opinion of the Pan-African Parliament on the proposal and shall transmit the opinion, if any, to the Assembly, which may adopt the proposal, taking into account the opinion of the Pan-African Parliament. 5. The amendment or revision shall enter into force thirty (30) days after the deposit of the instruments of ratification with the Secretary General by two-thirds of Member States. Article 25