By Jon Wright and William Milliken (June 29, 2017, 12:57 PM EDT) -- Under the Chenery doctrine — a bedrock principle of administrative law that traces its origin back to the 75-year-old U.S. Supreme Court case for which it is named — a reviewing court may not affirm an agency determination unless the agency adequately explains the reasons motivating that determination. In a series of rulings over the past several months, the U.S. Court of Appeals for the Federal Circuit has employed this doctrine to vacate decisions of the Patent Trial and Appeal Board that the Federal Circuit has viewed as insufficiently reasoned. The doctrine thus presents potential pitfalls for the unwary PTAB practitioner, and potential opportunities for the savvy one....