1. The competent authority of a Contracting State may request the Court of Justice to give a ruling on a question of interpretation of the Convention or of one of the other instruments referred to in Article 1 if judgments given by courts of that State conflict with the interpretation given either by the Court of Justice or in a judgment of one of the courts of another Contracting State referred to in point 1 or 2 of Article 2. The provisions of this paragraph shall apply only to judgments which have become res judicata .