Congress handed the Federal Circuit the job of grading district courts' papers any time a case raises a meaty question of patent law. The court has taken its role to heart. Although issues of how to handle a case — procedural matters — turn on the law of the circuit from which the case comes, Federal Circuit law trumps all else (save the Supreme Court) on patent law's substance.

Except sometimes even things having to do with procedure fall within the Federal Circuit's purview, as it held today. A district court in Vermont had applied Second Circuit rules in judging whether to grant a preliminary injunction against (what the plaintiff deemed) on-going patent infringement of a patent on "ballistic protective eyewear". The Second Circuit uses a two-tier test — a milder one for a preliminary injunction that maintains the status quo and a tougher standard for a p.i. that changes it. But the panel believed that, because "[s]ubstantive matters of patent infringement are unique to patent law, . . . the estimated likelihood of success in establishing infringement is governed by Federal Circuit law." Revision Military, Inc. v. Balboa Mfg. Co., No. 11-1628, slip op. 4 (Fed. Circ. Nov. 27, 2012). The court vacated the district court's denial of Revision's motion for preliminary injunction and sent it back "for redetermination in accordance with Federal Circuit criteria." Id. at 7.