This is from today's Indonesia - Iron or Steel Safeguards Appellate Body report:
5.60. In light of the above, we consider that, in order to constitute one of the "measures provided for in Article XIX", a measure must present certain constituent features, absent which it could not be considered a safeguard measure. First, that measure must suspend, in whole or in part, a GATT obligation or withdraw or modify a GATT concession. Second, the suspension, withdrawal, or modification in question must be designed to prevent or remedy serious injury to the Member's domestic industry caused or threatened by increased imports of the subject product. In order to determine whether a measure presents such features, a panel is called upon to assess the design, structure, and expected operation of the measure as a whole. In making its independent and objective assessment, a panel must identify all the aspects of the measure that may have a bearing on its legal characterization, recognize which of those aspects are the most central to that measure, and, thereby, properly determine the disciplines to which the measure is subject. As part of its determination, a panel should evaluate and give due consideration to all relevant factors, including the manner in which the measure is characterized under the domestic law of the Member concerned, the domestic procedures that led to the adoption of the measure, and any relevant notifications to the WTO Committee on Safeguards. However, no one such factor is, in and of itself, dispositive of the question of whether the measure constitutes a safeguard measure within the meaning of Article 1 of the Agreement on Safeguards.
(footnotes omitted)
I imagine that, in the context of the disputes over whether the Section 232 steel/aluminum tariffs constitute safeguard measures, the U.S. will be happy with this language: "a panel should evaluate and give due consideration to all relevant factors, including the manner in which the measure is characterized under the domestic law of the Member concerned, the domestic procedures that led to the adoption of the measure, and any relevant notifications to the WTO Committee on Safeguards."
Recall the long discussion of this issue that we had in the comments here: http://worldtradelaw.typepad.com/ielpblog/2018/03/eu-can-retaliate-immediately-against-trumps-metal-tariffs.html