This Post is the beginning of bi-weekly series geared toward post grant practitioners, grouped under the heading “Patent Praxis” Changes made to patent claims in reexamination must comport with 35 U.S.C. § 305. Perhaps the most well known prohibition of this statute is that claims cannot be broadened during reexamination. This statutory prohibition should apply whether the amended claim or new claim is introduced by the patent owner via amendment, or by the patent examiner through an Examiner’s Amendment. The latter situation was addressed by the Federal Circuit last year in Predicate Logic, Inc. v. Distributive Software, Inc., 544 F.3d 1298 (Fed. Cir. 2008). During a patent infringement suit brought by Predicate Logic against Distributive Software (Distributive), Distributive requested reexamination of the patent-in-suit, identified as the ’798 Patent. The ‘798 Patent is directed to a universal data measurement, analysis and control method used in software development. At the close of the reexamination, an Examiner’s Amendment was entered to place the reexamination proceedings in condition for issuance of a Notice of Intent to Issue a Reexamination Certificate (NIRC). Specifically, independent claim 1 of the ‘798 Patent was amended by the examiner to change “instantiating said at least one index” to -instantiating at least one said index-. Additionally, claim 1 was further amended to divide a single instantiating step into “first instantiating” and “second instantiating” steps. The Federal Circuit reversed a district court decision that held the ‘798 Patent claims invalid for impermissible broadening during reexamination as a result of the Examiner’s Amendment. The Federal Circuit found that the amendment changing “said at least one index” to -at least one said index- did not broaden the scope of claim 1. It reasoned that it could not conceive of any process that would infringe amended claim 1 without infringing original claim 1. As to the substitution of two instantiating steps for one, the court held that the original claim, when properly interpreted, required two instantiation steps and, consequently, the substitution did not result in a substantive change to claim 1. Ergo, no intervening rights under 35 U.S.C. § 307 would obtain. The Federal Circuit was not pleased with the reexamination record presented; admonishing both the patent owner and the USPTO for failing to create an adequate prosecution history to fulfill the public notice function of patents. This case demonstrates that patent owners are well advised to submit Interview Summary Statements (37 CFR § 1.560(b)) following approval of the Examiner’s Amendment. Of course, such statements are required in reexamination proceedings for substantive interview discussions, however, as even cosmetic issues will be subject to attack in any subsequent litigation, it is best to err on the side of caution when summarizing the content of an interview in a reexamination proceeding.