An inter partes review may not be instituted if, before the date on which the petition is filed, the petitioner or real party in interest filed a civil action challenging the validity of a claim of the challenged patent. See 35 U.S.C. § 315(a). Likewise, an inter parties review may not be instituted if the petition requesting the proceeding is filed more than 1 year after the date on which the petitioner, real party in interest, or privy is served with a complaint alleging infringement of the challenged patent. See 35 U.S.C. § 315(b). Three decisions recently designated as precedential by the PTAB provide further guidance on such bars to institution.