Article 19

1. [Revision of the Treaty] Subject to paragraph 2, this Treaty may be revised by a conference of the Contracting Parties. The convocation of any revision conference shall be decided by the Assembly.

2. [Revision or Amendment of Certain Provisions of the Treaty] Article 17(2) and (6) may be amended either by a revision conference, or by the Assembly according to the provisions of paragraph 3.

3. [Amendment by the Assembly of Certain Provisions of the Treaty]
a) Proposals for the amendment by the Assembly of Article 17(2) and (6) may be initiated by any Contracting Party or by the Director General. 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.
b) Adoption of any amendment to the provisions referred to in subparagraph a) shall require three-fourths of the votes cast.
c) Any amendment to the provisions referred to in subparagraph a) shall enter into force one month 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 which were members of the Assembly at the time the Assembly adopted the amendment. Any amendment to the said provisions thus accepted shall bind all the Contracting Parties at the time the amendment enters into force, and States and intergovernmental organizations which become Contracting Parties at a subsequent date.