172. This dispute arises out of a challenge brought by Mexico against certain legal instruments of the United States establishing the conditions for the use of a “dolphin-safe” label on tuna products. In particular, Mexico identified the following legal instruments as the object of its challenge: the United States Code, Title 16, Section 1385 (the “Dolphin Protection Consumer Information Act” or “DPCIA”); the United States Code of Federal Regulations, Title 50, Section 216.91 and Section 216.92 (the “implementing regulations”); and a ruling by a US federal appeals court in Earth Island Institute v. Hogarth (the “Hogarth ruling”). Taken together, the DPCIA, the implementing regulations, and the Hogarth ruling set out the requirements for when tuna products sold in the United States may be labelled as “dolphin-safe”. More specifically, they condition eligibility for a “dolphin-safe” label upon certain documentary evidence that varies depending on the area where the tuna contained in the tuna product is harvested and the type of vessel and fishing method by which it is harvested. In particular, tuna caught by “setting on” dolphins is currently not eligible for a “dolphin-safe” label in the United States, regardless of whether this fishing method is used inside or outside the Eastern Tropical Pacific Ocean (the “ETP”). The DPCIA and the implementing regulations also prohibit any reference to dolphins, porpoises, or marine mammals on the label of a tuna product if the tuna contained in the product does not comply with the labelling conditions spelled out in the DPCIA.