Law360, New York (April 1, 2015, 4:53 PM EDT) -- The U.S. Supreme Court recently ruled that final decisions in trademark registration opposition proceedings before the U.S. Patent and Trademark Office Trademark Trial and Appeal Board may preclude relitigation of the same issues in subsequent district court infringement actions. B&B Hardware Inc. v. Hargis Industries Inc., No. 13-352 (Mar. 24, 2015). The B&B Hardware decision rejects categorical rules governing the doctrine of issue preclusion based on administrative agency rulings, opting for a case-by-case application of principles from the Restatement (Second) of Judgments. Although the decision does not directly address inter partes challenges to patent validity under the Leahy-Smith America Invents Act, B&B Hardware suggests that certain issues decided in Patent Trial and Appeal Board AIA trials may trigger issue preclusion in subsequent district court infringement litigation....