Implications of Filing Subsequent Patent Applications in the United States (Part III)

“Some would argue that a subsequent application is best served when it incorporates one or more prior applications by reference. The doctrine of incorporation by reference is a way to include matter present in one document in the disclosure of another document. However, there are three issues of which to be aware.”

In Part I, the authors reviewed the law behind subsequent patent applications. In Part II, we reviewed the different types of subsequent applications. Part III will discuss some of the implications of these.

Written Description and Enablement and New Matter an applicant seeks to add new claims pursuant to a continuation or divisional application, U.S. Patent Law explicitly requires that the original specification provide adequate support for the new claims by the original specification satisfying the Section 112(a) written description and enablement requirements for the new claims. 35 U.S.C. § 120. The same is also true for continuation-in-part (CIP) applications claiming overlapping subject matter but not for claims comprising “new matter” because the new matter claimed must find support in additional disclosure, i.e., in material added to the CIP application itself.

No matter how the subsequent application is characterized, the specification (the written description, the drawings, and, possibly, the claims as filed) must still be enabling. See, e.g., Therasense, Inc. v. Becton, Dickinson and Co., 593 F. 3d 1289,1295 (Fed.Cir.2010), citing  In re Smolak, 24 C.C.P.A. 1132, 88 F.2d 838, 841 (1937) (“[T]he disclosures in [prior art] specifications … include the claims, the written specification, and the drawings.” (quotation omitted)). Whether a patent claim satisfies the written description requirement of 35 U.S.C. § 112(a) depends on whether the description “clearly allow[s] persons of ordinary skill in the art to recognize that [the inventor] invented what is claimed.” Vas-Cath Inc. v. Mahurkar, 935 F.2d 1555, 1562-63 (Fed. Cir. 1991) (internal quotation marks omitted) (quoting In re Gosteli, 872 F.2d 1008,1012 (Fed. Cir. 1989)). However, “ipsis verbis disclosure is not necessary to satisfy the written description requirement of section 112, but keep in mind that non-US practice may require using identical language).” Fujikawa v. Wattanasin, 93 F.3d 1559, 1570 (Fed. Cir. 1996) (for those who do not speak Latin, “ipsis verbis” means “in the same words” or “in the precise words used in the relevant source). “[T]he disclosure need only reasonably convey to persons skilled in the art that the inventor had possession of the subject matter in question.” Id. Further, patent figures may be considered for enablement arguments but are not assumed to be drawn to scale. Hockerson-Halberstadt, Inc. v. Avia Group International, Inc., 222 F.3d 951,956 (Fed. Cir. 2000) (“patent drawings do not define the precise proportions of the elements and may not be relied on to show particular sizes if the specification is completely silent on the issue.”).

Therefore, whatever and however the specific articulation, the enablement test requires an objective inquiry into the four corners of the specification from the perspective of a person of ordinary skill in the art. Based on that inquiry, the specification must describe an invention understandable to that skilled artisan and show that the inventor actually invented the invention claimed. Ariad Pharm., Inc. v. Eli Lilly & Co., 598 F.3d 1336, 1351 (Fed. Cir. 2010) (en banc).

Substantial evidence supports a finding that the specification satisfies the written description requirement when “the essence of the original disclosure” conveys the necessary information regardless of how it conveys such information, and even when the disclosure’s words “[a]re open to different interpretation[s].” In re Wright, 866 F.2d 422, 424-25 (Fed. Cir. 1989) (citations and internal quotation marks omitted, emphasis in original); see also Falko-Gunter Falkner v. Inglis, 448 F.3d 1357, 1365-66 (Fed. Cir. 2006) (finding substantial evidence supported written description based on “several passages in the [patentee’s] application” and the unrebutted “testimony of [the patentee’s] expert,” which showed that skilled artisans would understand the invention); Novozymes A/S v. DuPont Nutrition Biosciences APS, 723 F.3d 1336, 1346 (Fed. Cir. 2013) (discussing the metaphor from In re Ruschig, 379 F.2d 990, 994-95 (CCPA 1967) that a disclosure should “provide sufficient ‘blaze marks’ to guide a reader through the forest of disclosed possibilities toward the claimed compound”). If a subsequent application conveys the necessary information, a continuation application may be warranted. If it does not, a continuation application is not warranted and new matter to satisfy enablement must be added via a CIP application or by filing a new application.


A continuation application and a divisional application each still require most of what a 35 USC §111 application requires, although in a continuation and divisional applications the USPTO recognizes the power of attorney and the inventors’ declarations filed in the parent application. However, because the inventors’ declarations relate to the claims, care should be taken to ensure that the named inventors in a continuation and divisional application are only those who are legally inventors with respect to that which is claimed in that subsequent application.

Prosecution History Estoppel and Disclaimer

A patentee may file a continuation application with different claims and terms, keeping in mind that “different claim terms are presumed to have different meanings.” See Helmsderfer v. Bobrick Washroom Equip., Inc., 527 F.3d 1379, 1382 (Fed. Cir. 2008). “Although a parent patent’s prosecution history may inform the claim construction of its descendant[,] prosecution history is irrelevant to the meaning of [a] limitation [if] the two patents do not share the same claim language.”, Inc. v. Lansa, Inc., 346 F.3d 1374, 1383 (Fed. Cir. 2003). Notably, “the prosecution of one claim term in a parent application will generally not limit different claim language in a continuation application.” Invitrogen Corp. v. Clontech Labs., Inc., 429 F.3d 1052, 1078 (Fed. Cir. 2005).

However, if a continuation application includes language incorporating one or more parent applications by reference, “[t]he incorporated patents are ‘effectively part of the host [patents] as if [they] were explicitly contained therein’ [and, as] a result, the disclaimers of the incorporated patents are part of the asserted patents.” X2Y Attenuators, LLC v. International Trade Comm’n, 757 F.3d 1358, 1362-63 (Fed. Cir. 2014) (quoting Telemac Cellular Corp. v. Topp Telecom, Inc., 247 F.3d 1316, 1329 (Fed. Cir. 2001) (some internal citations omitted); see also Cordis Corp. v. Boston Scientific Corp., 658 F.3d 1347, 1356 n.5 (Fed. Cir. 2011) (“[A] disclaimer in the parent application carries forward into the construction of the same claim term in the child.”) Thus, under this general principle, disclaimer of scope found in a prior application, whether before the USPTO or during litigation, may apply to a subsequent patent, as discussed below, and can be a general deterrent to incorporation by reference.

Moreover, although a family of applications may share all or part of a common specification, that common specification – by itself or even in combination with a shared terminal disclaimer – is not enough to show that a claim in one patent is representative of any other claims. SimpleAir, Inc. v. Google LLC, 884 F.3d 1160,1166 (rejecting shared specification and terminal disclaimer as a basis for finding claim preclusion because “‘it is the claims of the patent which define the invention’”) (quoting Altoona Publix Theatres, Inc. v. Am. Tri-Ergon Corp., 294 U.S. 477, 487 (1935)). Further, while the specification must offer a written description sufficient to support each claimed invention, a specification might describe multiple, distinct inventions, as is often the case with divisional applications. See Bourns, Inc. v. United States, 537 F.2d 486, 492 (Ct. Cl. 1976) (“[T]he claims may be multiplied either because there are multiple facets to the invention and claims to the separate parts and subparts are necessary to protect the invention …”).

However, because a subsequent application follows an application that will likely have its own file wrapper, prosecution disclaimer and/or estoppel may arise for the subsequent application. “The doctrine of prosecution disclaimer … preclud[es] patentees from recapturing through claim interpretation specific meanings disclaimed during prosecution.” See Omega Eng’g, Inc, v. Raytek Corp., 334 F.3d 1314, 1323 (Fed. Cir. 2003) (see also Aylus Networks, Inc. v. Apple Inc., 856 F.3d 1353, 1360 (Fed. Cir. 2017) (“Ultimately, the doctrine of prosecution disclaimer ensures that claims are not construed one way in order to obtain their allowance and in a different way against accused infringers.” (internal quotation marks and citation omitted)). Prosecution disclaimer occurs “when a patentee, either through argument or amendment, surrenders claim scope during the course of prosecution.” Heuft Systemtechnik GmbH v. Indus. Dynamics Co., Ltd., 282 Fed.Appx. 836, 839 (Fed. Cir. 2008). Prosecution history disclaimer in a parent application may bind continuation or continuation-in-part applications if they involve the same claim limitation. Omega Eng’g, Inc. v. Raytek Corp., 334 F.3d 1314, 1333 (Fed. Cir. 2003) (“As long as the same claim limitation is at issue, prosecution disclaimer made on the same limitation in an ancestor application will attach.”). But “[w]hen the purported disclaimers are directed to specific claim terms that have been omitted or materially altered in subsequent applications (rather than to the invention itself), those disclaimers do not apply.” Saunders Grp., Inc. v. Comfortrac, Inc., 492 F.3d 1326, 1333 (Fed. Cir. 2007). “In general, a prosecution disclaimer will only apply to a subsequent patent if that patent contains the same claim limitation as its predecessor.” Regents of Univ. of Minn. v. AGA Med. Corp., 717 F.3d 929, 943 (Fed Cir. 2013). It also may be possible to rescind a disclaimer previously found in an earlier patent so that the continuation patents are not bound by the disclaimer. See Hakim v. Cannon Avent Grp., PLC, 479 F.3d 1313, 1318 (Fed. Cir. 2007) (“[A] disclaimer made during prosecution can be rescinded, permitting recapture of the disclaimed scope.”); X2Y Attenuators, 757 F.3d at 1363 (noting that “incorporation by reference does not convert the invention of the incorporated patent into the invention of the host patent,” and “it is certainly possible that a clear and unmistakable disavowal in an incorporated patent is no longer so when placed in the context of the disclosure of the host patent” (internal quotations omitted)).

In the context of a prosecution disclaimer, to effectively rescind the disclaimer “the prosecution history must be sufficiently clear to inform the examiner that the previous disclaimer, and the prior art that it was made to avoid, may need to be revisited.” Id. For example, presume an applicant adopts an explicit claim-narrowing limitation to achieve immediate issuance of a patent containing the narrowed claims and postpones further arguments about claims that lack the narrowing limitation to the prosecution of a continuation application. Without more, that process does not imply a disclaimer as to claims later issued in the continuation that lack the first patent’s express narrowing limitation. Sanofi v. Watson Laboratories Inc., 875 F.3d 636,650 (Fed.Cir. 2017). On many occasions this may lead to significant “forward momentum” during prosecution: the examiner, after having finally reviewed the parent application, perhaps with the aid of a telephone, video, or personal interview, may better understand what the inventors are trying to accomplish. Thereafter, the examiner may be more willing to pick up one continuation for review, then another, and another. In one scenario prosecuted by one of the authors for a series of medical devices (see U.S. Patent Nos. 9,144,512 (parent); 9,439,803 (Continuation of parent); 10,299,957 (Continuation 2 of parent); 9,408,743 (CIP of parent); 9,445,938 (Continuation of CIP)), the examiner was simply not buying the applicants’ written patentability arguments over the prior art cited by the examiner, even with telephone interviews and inventor affidavits. Finally, the client and his representative mutually concluded that a show and tell personal interview with the examiner and her SPE was the only path to success. Bingo! Five granted patents later the applicants are still prosecuting at least one continuation application, with claim scope as originally filed in the parent. (One might argue the same success would have been accomplished by appealing the parent application – perhaps, but the inventors now have five+ patents for the competition to worry about, not one.)

Incorporation by Reference

Some would argue that a subsequent application is best served when it incorporates one or more prior applications by reference. The doctrine of incorporation by reference is a way to include matter present in one document in the disclosure of another document. Incorporation by reference provides “a method for integrating material from various documents into a host document[]. . . by citing such material in a manner that makes clear that the material is effectively part of the host document as if it were explicitly contained therein.” As an aside, note that a rule prohibiting incorporation by reference in IPR proceedings is set forth in 37 C.F.R. § 42.6(a)(3): “(3) Incorporation by reference; combined documents. Arguments must not be incorporated by reference from one document into another document. Combined motions, oppositions, replies, or other combined documents are not permitted.” Paice LLC v. Ford Motor Co., 881 F.3d 894,906 (Fed. Cir. 2018), quoting Advanced Display Sys., Inc. v. Kent State Univ., 212 F.3d 1272, 1282 (Fed. Cir. 2000).

“To incorporate material by reference, the host document must identify with detailed particularity what specific material it incorporates and clearly indicate where that material is found in the various documents.” Id. Whether and to what extent material has been incorporated by reference is a question of law that we review de novo.” Harari v. Lee, 656 F.3d 1331, 1334 (Fed. Cir. 2011). [T]he standard of one reasonably skilled in the art should be used to determine whether the host document describes the material to be incorporated by reference with sufficient particularity.” Paice LLC, 881 F.3d at 906. Incorporation language must be read in context and holistically.

Towards that end, some would argue that including an express incorporation by reference to the priority application in a subsequent application acts as insurance against filing errors in which all intended disclosure is not filed in the continuation application, even when the disclosures of the continuation application and its priority application are identical. Neifeld, III(A)(3).

However, there are three issues of which to be aware. First, a subsequent application ought to be more-or-less exactly that from which it derives (but for new matter in a CIP). Thus, incorporation by reference is usually unnecessary. Second, in some non-U.S. jurisdictions, all that which is incorporated by reference is required to be added to the issuing application and translated, unnecessarily adding to costs. Third, as discussed before, prosecution disclaimer may arise.



Warning & Disclaimer: The pages, articles and comments on do not constitute legal advice, nor do they create any attorney-client relationship. The articles published express the personal opinion and views of the author as of the time of publication and should not be attributed to the author’s employer, clients or the sponsors of

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2 comments so far.

  • [Avatar for Kenneth J Hughes]
    Kenneth J Hughes
    November 16, 2020 08:58 pm

    I greatly appreciate your clear explanations and adept selection of key citations throughout this series. Thank you.

  • [Avatar for Pro Say]
    Pro Say
    November 14, 2020 04:01 pm

    Nice, worthwhile series guys — thanks much.