The Federal Circuit has doubled down on the requirement that courts evaluating indefiniteness must look beyond the claims themselves. In its January 27 precedential decision in Nature Simulation Systems v. Autodesk, a Federal Circuit majority held that Northern District of California Magistrate Judge Sallie Kim applied an incorrect standard in invalidating claims as indefinite based on “unanswered questions” raised by ambiguity in certain terms. Additionally, the majority ruled that the lower court erred by requiring that such questions be answered by “the claim language, standing alone”. Rather, the correct standard is to interpret claims “in light of the specification, the prosecution history, and other relevant evidence”, the majority explained. The opinion prompted a dissent from Circuit Judge Timothy Dyk.