Patent Office Clarifies Standard For Indefiniteness In AIA Post-Grant Proceedings

On January 6, 2021, the U.S. Patent and Trademark Office (USPTO) issued a memorandum clarifying the standard for indefiniteness in post-grant proceedings under the America Invents Act (AIA). Specifically, the USPTO decided on the Nautilus standard, under which a claim is invalid as indefinite "if the claim, read in light of the specification delineating the patent, and the prosecution history, fails to inform, with reasonable certainty, those skilled in the art about the scope of the invention." The memorandum is available here.

Background

Title 35 U.S.C. § 112(b) provides that a patent shall have "one or more claims particularly pointing out and distinctly claiming the subject matter which the inventor or a joint inventor regards as the invention." The section, therefore, requires that patent claims be definite. A determination of whether a patent claim is indefinite can be made by the USPTO during examination, on appeal from examination, and during post-grant