Judgments delivered by the Court (or by one of its Chambers) in disputes between States are binding upon the parties concerned. Article 94 of the United Nations Charter lays down that "each Member of the United Nations undertakes to comply with the decision of [the Court] in any case to which it is a party". Judgments are final and without appeal. If either of the parties challenges their scope or meaning, it has the option to request an interpretation. In the event of the discovery of a fact hitherto unknown to the Court which might be a decisive factor, either party may apply for revision of the judgment. As regards advisory opinions, it is usually for the United Nations organs and specialized agencies requesting them to give effect to them or not by whatever means are appropriate for them.