Article 11

(1) [Amending of Certain Provisions by the Assembly] The Assembly may amend the definitions contained in Article 2(i) and (ii), as well as Articles 3(1)(c), 9(1)(c) and (d), 9(4), 10(1)(a) and 14.

(2) [Initiation and Notice of Proposals for Amendment]
(a) Proposals under this Article for amendment of the provisions of this Treaty referred to in paragraph (1) may be initiated by any Contracting Party or by the Director General.
(b) Such proposals shall be communicated by the Director General to the Contracting Parties at least six months in advance of their consideration by the Assembly.
(c) No such proposal shall be made before the expiration of five years from the date of entry into force of this Treaty under Article 16(1).

(3) [Required Majority] Adoption by the Assembly of any amendment under paragraph (1) shall require four-fifths of the votes cast.

(4) [Entry Into Force]
(a) Any amendment to the provisions of this Treaty referred to in paragraph (1) shall enter into force three months after written notifications of acceptance, effected in accordance with their respective constitutional processes, have been received by the Director General from three-fourths of the Contracting Parties members of the Assembly at the time the Assembly adopted the amendment. Any amendment to the said provisions thus accepted shall bind all States and Intergovernmental Organizations that were Contracting Parties at the time the amendment was adopted by the Assembly or that become Contracting Parties thereafter, except Contracting Parties which have notified their denunciation of this Treaty in accordance with Article 17 before the entry into force of the amendment.
(b) In establishing the required three-fourths referred to in subparagraph (a), a notification made by an Intergovernmental Organization shall only be taken into account if no notification has been made by any of its member States.