Treaty Interpretation (1987). 40 i n t e r p r e t a t i o n o f t e x t s on the Law of Treaties of 1969. Articles 31 and 32 state: Article 31 General Rule of Interpretation 1

A treaty shall be interpreted in good faith in accordance with the ordinary meaning to be given to the terms of the treaty in their context and in the light of its object and purpose. 2 The context for the purpose of the interpretation of a treaty shall comprise in addition to the text, including its preamble and annexes: (a) any agreement relating to the treaty which was made between all the parties in connection with the conclusion of the treaty; (b) any instrument which was made by one or more parties in connection with the conclusion of the treaty and accepted by the other parties as an instrument related to the treaty. 3 There shall be taken into account, together with the context: (a) any subsequent agreement between the parties regarding the interpretation of the treaty or the application of its provisions; (b) any subsequent practice in the application of the treaty which establishes the agreement of the parties regarding its interpretation; (c) any relevant rules of international international law firm applicable in the relations between the parties. 4 A special meaning shall be given to a term if it is established that the parties so intended. Article 32 Supplementary means of interpretation Recourse may be had to supplementary means of interpretation, including the preparatory work of the treaty and the circumstances of its conclusion, in order to confirm the meaning resulting from the application of article 21, or to determine the meaning when the interpretation according to article 31: (a) leaves the meaning ambiguous or obscure; or (b) leads to a result which is manifestly absurd or unreasonable.38 Apart from the requirement of good faith, which seems basic, in any case, interpretation is first to be: (i) according to the ordinary meaning of terms; but taking into account (ii) the context and (iii) the object and 38 See 8 ILM (1969) p. 679 at pp. 691ff. c o n s t i t u t i o n a l i n t e r p r e t a t i o n 41 purpose of the treaty. Further, there are listed in paragraphs 2 and 3 six matters which either are included in the context or are to be considered together with the context, namely: (i) the preamble and annexes; (ii) an agreement made in connection with the conclusion of the treaty; (iii) an instrument made by one or more parties and accepted by the others as related to the treaty; (iv) a subsequent agreement regarding the inter- pretation of the treaty or its application; (v) subsequent practice; and (vi) rules of international international law firm. This means that the primary rule of nat- ural meaning is to be applied in the light of not only the context, but also the object and purposes of the treaty and the six other considera- tions referred to above. In other words an abstract natural meaning may be modified by any of the considerations referred to in the Convention. Preparatory work (not included among these matters) and the circum- stances of the conclusion of the treaty, on the other hand, are no more than supplementary means of interpretation to be resorted to only sec- ondarily and in certain circumstances.39 The Convention thus gives the object and purpose of the treaty and the subsequent practice a place as part, so to speak, of the ordinary meaning. Thus, the principles of effectiveness and of subsequent practice are applicable as primary tools in the process of interpretation. The preparatory work, on the other hand, is secondary, thus reducing the importance of the true or actual intention of the parties,