A few years ago, I did two posts on the difference between "interpretations" by WTO Members under WTO Agreement Article IX:2 and "clarifications" by panels and the Appellate Body under DSU Article 3.2. Based on the statements by the Appellate Body quoted in the posts, it seemed to me that, in essence, "interpret" means "clarify" and "clarify" means "interpret."
In its recent Cloves report, the Appellate Body has now given us a new term to throw into the mix: "interpretative clarifications," which are made in subsequent agreements under VCLT Article 31(3)(a). Here's what they said:
269. In the light of our characterization of paragraph 5.2 of the Doha Ministerial Decision as a subsequent agreement between the parties within the meaning of Article 31(3)(a) of the Vienna Convention, we turn now to consider the meaning of Article 2.12 of the TBT Agreement in the light of the clarification of the term "reasonable interval" provided by paragraph 5.2. We observe that, in its commentaries on the Draft articles on the Law of Treaties, the ILC states that a subsequent agreement between the parties within the meaning of Article 31(3)(a) "must be read into the treaty for purposes of its interpretation".473 As we see it, while the terms of paragraph 5.2 must be "read into" Article 2.12 for the purpose of interpreting that provision, this does not mean that the terms of paragraph 5.2 replace or override the terms contained in Article 2.12. Rather, the terms of paragraph 5.2 of the Doha Ministerial Decision constitute an interpretative clarification to be taken into account in the interpretation of Article 2.12 of the TBT Agreement. (emphasis added)
So, now we have "interpretations" by the Members under IX:2, "interpretative clarifications" by the Members under VCLT 31(3)(a), and "clarifications" by panels and the AB under DSU 3.2. I think I understand all of this, although I eagerly await any future interpretations, clarifications or interpretative clarifications of the issue.