On March 23, the US Court of Appeals for the Federal Circuit issued a decision endorsing an exception to the estoppel provisions for inter partes review (IPR) under 35 U.S.C § 315(e). Shaw Industry Group, Inc. v. Automated Creel Systems, Inc., No. 2015-1116, 2015-1119 (Fed. Cir. Mar. 23, 2016). The estoppel provisions of § 315(e) prevent a party from raising issues in subsequent proceedings that were "raised or reasonably could have [been] raised during [a prior] inter partes review." 35 U.S.C. §§ 315(e)(1) and (2). In Shaw, the Federal Circuit was asked to review a final decision issued by the Patent Trial and Appeal Board (PTAB) in an IPR and a petition for a writ of mandamus instructing the PTAB to institute another IPR on grounds from the original petition that the PTAB had held were "redundant." Shaw, slip op. at 6, 9-10. Shaw argued that the redundancy ruling and estoppel provisions of § 315(e) prevented it from raising those claims in any forum. Id. at 9-10. In denying the petition for writ of mandamus, the Federal Circuit focused on the "during" language of § 315(e), drawing a distinction between the petition for an IPR and the instituted IPR itself. Shaw, slip op. at 11. The court held "the IPR does not begin until instituted[,]" and thus, grounds asserted in a prior petition for IPR, but not considered in an instituted IPR, are not raised and could not be reasonably raised "during the IPR." Id. (emphasis in the original).