Article 10 Vienna Convention on the Law of Treaties

Authentication of the text

The text of a treaty is established as authentic and definitive:

(a) by such procedure as may be provided for in the text or agreed upon by the States participating in its drawing up; or

(b) failing such procedure, by the signature, signature ad referendum or initialling by the representatives of those States of the text of the treaty or of the Final Act of a conference incorporating the text.

See also: Article 9 Vienna Convention on the Law of Treaties