Article 33(4) of the Vienna Convention on the Law of the Treaties550 states that conflicts between authentic texts of equal authority should be resolved by:

(1) applying the principles specified in Articles 31 (General rule of interpretation) and 32 (Supplementary means of interpretation) of the Vienna Convention;

(2) and, if necessary, by taking into account the object and purpose of the agreement, i.e. the Preamble.

The second scenario involves differences in interpretation of authentic and official texts. While, certainly, a distinction has to be drawn between the two – the former being authoritative – official versions of the Convention cannot be regarded as irrelevant. The interpreter might focus, and rightly so, on the authentic versions of the Convention as the expression of agreement between the parties, but reference to the official versions can be crucial as well in determining the states’ expectations. This is due to the fact that some parties to the Convention agreed to the authentic versions only because they were recognised to correspond with the respective official text. Hence, the merit of official versions of agreements is generally being regarded as more valuable for the interpretation of the treaty than extrinsic materials.551

Given the fact that during the whole process of drafting the convention English has been the working language, it seems highly likely that, in any case, the English version of the Convention will receive greater attention from any interpreter.

548 BS Murty, The International Law of Diplomacy : The Diplomatic Instrument and World Public Order (Martinus Nijhoff Publishers 1989) at 649.

549 See J Hardy, The Interpretation of Plurilingual Treaties by International Courts and Tribunals (Oxford University Press 1961) at 82.

550 1969 Vienna Convention on the Law of Treaties (adopted 23 May 1969, entered into force 27 January 1980) 1155 UNTS 331 (Vienna Convention).

551 Hardy, The Interpretation of Plurilingual Treaties by International Courts and Tribunals at 651.