The “concurrent-remedies doctrine” holds that “when the jurisdiction of the federal court is concurrent with that of law, or the suit is brought in aid of a legal right, equity will withhold its remedy if the legal right is barred by the local statute of limitations.” In Sierra Club v. Luminant Energy, that doctrine would have barred a private litigant’s claim for an injunction when a damages claim was time-barred – but it was held not to apply to a request for injunctive relief brought by the U.S. in its capacity as sovereign. On the merits of the request, the panel majority noted that “the statute of limitations that barred the legal relief [of damages] does not itself bar equitable relief unless it constitutes a penalty,” and left the question of whether the relief was in fact a penalty for the district court on remand. A dissent reasoned that “both of these so-called forms of injunctive relief are really just time-barred penalties in disguise,” would have affirmed dismissal of the entire case on limitations grounds, and avoided the issue about applying the concurrent-remedies doctrine to sovereigns. No. 17-10235 (Oct. 1, 2018).