The US Court of Appeals for the Federal Circuit imposed limits on what the Patent Trial and Appeal Board (PTAB) is authorized to do by statute when dealing with challenged claims in an inter partes review (IPR) that it finds to be too indefinite to apply prior art. Samsung Elecs. Am., Inc. v. Prisua Eng’g Corp., Case Nos. 19-1169, -1260 (Fed. Cir. Feb. 4, 2020) (Bryson, J).