At paras 6, 8 the Appeals Chamber held:

6. In order to consider NATO’s Request, the Appeals Chamber must find that NATO has standing to bring it before the Appeals Chamber. It is clear under Rule 108bis (A) that it is “a State” that “may […] file a request for review of the [Trial Chamber’s interlocutory] decision by the Appeals Chamber […].” Similar to Rule 108bis, the plain language of Rule 54bis only makes reference to issuance of a binding order to produce documents and information to “a State” who may then seek review of that order under Rule 108bis.[1] NATO, as an international organization formed by an alliance of 26 individual sovereign States joined by treaty,[2] does not meet the definition of a State under the International Tribunal’s Rules.[3] Therefore, in order to consider whether it has competence to review NATO’s Request under Rule 108bis, the Appeals Chamber must first determine, proprio motu, whether the Trial Chamber erred in issuing a Rule 54bis order against NATO as an international organisation.[4]

8. […] The Appeals Chamber recalls that the basis for a Trial Chamber’s binding Rule 54bis order to produce is found in Article 29 and paragraph four of Security Council resolution 827 (1993).[5] On the face of those texts, only “States” have the obligation to cooperate with the International Tribunal in the investigation and prosecution of persons accused of committing serious violations of international humanitarian law[6] and to comply with requests or orders for judicial assistance.[7] However, the Appeals Chamber agrees with the Trial Chamber in Simić that “States” refers to all Member States of the United Nations, whether acting individually or collectively and, under a “purposive construction” of the Statute of the International Tribunal, Article 29 applies to “collective enterprises undertaken by States” such as an international organization or its competent organ.[8] It is the general rule in the jurisprudence of the International Tribunal that the rules of treaty interpretation in international law apply to the Statute of the International Tribunal.[9] Article 31(1) of the Vienna Convention on the Law of Treaties[10] provides that “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.” The Appeals Chamber further agrees with the Simić Trial Chamber that “[t]he mere fact that the text of Article 29 is confined to States and omits reference to other collective enterprises of States does not mean it was intended that the International Tribunal should not also benefit from the assistance of States acting through such enterprises.”[11] Indeed, the Appeals Chamber recalls that “[i]n the final analysis, the International Tribunal may discharge its functions only if it can count on the bona fide assistance and cooperation”[12] of States and the purpose of Article 29 is to require the full cooperation of States with the International Tribunal in fulfilling its crucial mandate. To interpret Article 29 in such a way that the International Tribunal would be prevented from obtaining information or documents from a State when it was acting through an international organization, would undermine the essence of the International Tribunal’s functions. Thus, the Appeals Chamber finds that the International Tribunal’s Article 29 power to issue binding orders is as applicable to international organizations as collective enterprises of States, as it is to individual Member States.(emphasis added).