This is from Article 28.11 of the TPP Dispute Settlement Chapter:
3. The panel shall consider this Agreement in accordance with applicable rules of interpretation under international law as reflected in Articles 31 and 32 of the Vienna Convention on the Law of Treaties (1969). In addition, with respect to any obligation of any WTO agreement that has been incorporated into this Agreement, the panel shall also consider relevant interpretations in reports of panels and the WTO Appellate Body adopted by the WTO Dispute Settlement Body. The findings, determinations and recommendations of the panel shall not add to or diminish the rights and obligations of the Parties under this Agreement.
Based on this provision, the role of adopted WTO panel and AB reports in TPP dispute settlement is somewhat clear, although there is plenty of room for disagreement. But how about the role of adopted and unadopted GATT panel reports, Article 22.6 and Article 21.3 arbitration awards, the one WTO panel report which was never adopted, and WTO panel/AB reports that have been issued or circulated but not yet considered for adoption?