Enforcement and Non-waiver of 37 C.F.R. § 42.104(b)(4) and Permissible Uses of General Knowledge in Inter Partes Reviews

The USPTO will enforce, and no longer waive, 37 C.F.R. § 42.104(b)(4), which requires an IPR petition to specify where each claim element is found in the prior art patents or printed publications relied upon. As a result, applicant admitted prior art, expert testimony, common sense and other general knowledge may not supply a missing claim limitation, though it may still support a motivation to combine or show the knowledge of a person of ordinary skill. The memorandum applies to petitions filed on or after September 1, 2025. Petitioners must now find every claim limitation in patents or printed publications. They cannot fill a gap with AAPA, expert testimony or common sense, and under 35 U.S.C. § 312(a)(4) the Board shall deny a petition that does not comply with Rule 104(b)(4). Patent owners gain a clearer statement of the basis of the challenge and a firm ground for opposing petitions that rely on general knowledge for a limitation. The memorandum rests on 35 U.S.C. §§ 312(a)(3), 312(a)(4) and 316(b), and on the Federal Circuit's Qualcomm decisions (24 F.4th 1367 and 134 F.4th 1355). It also notes that Rule 104(b)(4) may in some cases be narrower than § 311(b). WHAT IT DOES: Ends the Board's waiver of Rule 104(b)(4). AAPA, expert testimony, common sense and other non-patent, non-printed-publication evidence (collectively, general knowledge) may not be used to supply a missing claim limitation. Under 35 U.S.C. § 312(a)(4) the Board shall deny a petition that fails to comply. General knowledge may still support a motivation to combine or show the knowledge of a person having ordinary skill in the art. WHO AND WHEN: Directed to members of the Board, and issued July 31, 2025. It applies to any petition for IPR filed on or after September 1, 2025. KEY QUOTE: "General knowledge may still be used in an IPR to support a motivation to combine or to demonstrate the knowledge of a person having ordinary skill in the art." (p. 1) EARLIER GUIDANCE AFFECTED: Supersedes the August 18, 2020 Memorandum, "Treatment of Statements of the Applicant in the Challenged Patent in Inter Partes Reviews Under § 311," and the June 9, 2022 Memorandum, "Updated Guidance on the Treatment of Statements of the Applicant in the Challenged Patent in Inter Partes Reviews Under § 311." Both had indicated that the Board was waiving enforcement of Rule 104(b)(4). PRACTICE TIP: For IPR petitions filed on or after September 1, 2025, map every claim limitation to a patent or printed publication. Use AAPA, expert testimony or common sense only for motivation to combine or for the skilled artisan's knowledge, never to supply a missing limitation. Issued by Coke Morgan Stewart, Acting Under Secretary of Commerce for Intellectual Property and Acting Director of the United States Patent and Trademark Office.