Disparaging the prior art/alternative embodiments, especially in combination with a limited characterization of the disclosed embodiments (e.g. only describe embodiments without the disparaged characteristics), may forfeit claim scope on claims that on their face might otherwise include the disparaged embodiments (if not literally, then at least under DoE), as described here and here.

For instance consider the following case outlined in this 2006 article:

In Toro, claim 1 read in part “said cover including means for increasing the pressure developed by” blower. The specification stated that the invention is “advantageous in that it automatically restricts the size of the inlet … without having the operator manually insert or remove a replaceable ring.” At issue was the question of whether a separate ring/structure would be considered to be an infringement of claim 1. According to the Court of Appeals for the Federal Circuit (CAFC), “there [was] no doubt that the specification … disclose[d] the separate ring/structure… it d[id] so by noting inferiority of a device in which the operator manually insert[ed] or remove[d] a replaceable ring (Toro at 1334).” However, the disclosed separate ring/structure was not claimed. The subject matter directed to the blower wherein the operator manually inserts or removes a replaceable ring was held to be dedicated to the public (Id.).

[As a side note, I believe the article incorrectly characterizes this outcome as application of the "disclosure-dedication" rule (disclosed but unclaimed embodiments are not covered under DoE), whereas it is actually application of narrowed claim construction due to disparaging prior art/limited characterization of the invention (since the "forfeited" scope was not excluded on the face of the broad claim).]

The point for bringing up the article is that, as bolded, disparaging the prior art in itself at least provides written description of the disparaged embodiments, and likely enablement as well (which can rely more heavily on PHOSITA knowledge).

So the question is, can an applicant amend claims to cover a disparaged embodiment that would otherwise be excluded from the scope of a broad claim in a claim construction proceeding, assuming it was not an original claim? Or, reiterating the title, "do disparaged embodiments lack claim support"?

Although I won't muddy the question with this twist, the case at hand actually disparages a prior art embodiment repeatedly, but then also includes a "catchall" that would seem to include the disparaged embodiment. Therefore, it is not clear which controls.

  • It is worth trying - but even if you get past the examination this might be a weakness in the future defensibility of the claim. Also, in the climate over the last few years, it is very rare that DoE helps a patent owner.
    – George White
    May 10, 2018 at 2:21
  • @GeorgeWhite Okay, thanks. In this case, I am actually on the defending end of a competitor patent, and don't want to highlight the disparagement to the examiner/applicant (e.g. via protest, TPS) if it will provide an opportunity for amendment to explicitly cover the disparaged embodiment. I.e. if disparaged embodiments can be claimed, I would rather let the broad claim pass and argue for narrow claim construction in a non-infringement scenario.
    – user132162
    May 10, 2018 at 18:49

3 Answers 3


Do disparaged embodiments lack claim support?


I will preface this by saying that, much to my frustration, I could not find a case on all-fours with what you are proposing. It could well a novel situation1.

But there are two well-established principles that are related: claims are interpreted to exclude disparaged subject matter, and claims without essential elements lack support. I believe these two in combination provide the answer: yes, disparaged embodiments lack claim support.

Disparagement leads to narrowed claims

When an embodiment is consistently disparaged so as to make clear that it is outside of the scope of the patent, then the claims must be interpreted to exclude it.

This is well established. Ultimate Pointer2 is a recent CAFC authority for this, but it's much older. The most notable holding of the decision is:

At every turn, Nintendo argues, the specification of the ’729 patent extolls direct pointing and disparages indirect pointing. Because the inventor described his invention as encompassing direct pointing and repeatedly criticized indirect pointing, Nintendo continues, Ultimate Pointer may not now claim that indirect pointing is within the claim scope.

We agree with Nintendo that the district court did not err in construing “handheld device” as “handheld direct pointing device.” …

Taken together, the repeated description of the invention as a direct-pointing system, the repeated extolling of the virtues of direct pointing, and the repeated criticism of indirect pointing clearly point to the conclusion that the “handheld device” in claims 1, 3, 5, 6, and 12 is limited to a direct-pointing device.

In other words, where the description consistently disparages X so as to make clear that the applicant is disavowing X, then the claims must be interpreted so as to exclude X.

But what if the claims are unambiguous?

Ultimate Pointer does not expressly consider what happens if the claims are unambiguous. That is, what if you cannot interpret the claims to avoid disavowed subject matter? Indeed, I couldn't see that anyone had directly considered this.

However, I think there is an answer by analogy with the "essential element test"3.

That is, it is well established that for claims to have support, the inventor must have been in possession of the invention at the time of application4. The "essential element test" provides that if a certain element is noted in the description as essential, then the inventor cannot be regarded as being in possession of an invention without that element. Such a claim therefore lacks support.

This principle was established in Gentry5. This is an older, formative decision, but is still considered good law.

In this case, Gentry had enforced claims relating to a sectional sofa with a center console and controls for reclining the seats. The alleged infringer argued, among other things, that this was invalid for lacking support, because the description provided that the controls were on the console. The appellate court agreed:

Accordingly, when viewed in its entirety, the disclosure is limited to sofas in which the recliner control is located on the console. …

Because of this, claims could not be broader: the controls must be on the console.

Here, as indicated above, it is clear that Sproule [the inventor] considered the location of the recliner controls on the console to be an essential element of his invention. Accordingly, his original disclosure serves to limit the permissible breadth of his later-drafted claims. …

Gentry referred to an earlier decision, which referred to allowing an applicant to claim broader than the specific embodiment. The court distinguished this based on the level of description.

The claims at issue in Rasmussen, which were limited to the generic step of “adheringly applying” one layer to an adjacent layer, satisfied the written description requirement only because “one skilled in the art who read [the] specification would understand that it is unimportant how the layers are adhered, so long as they are adhered.” Here, on the contrary, one skilled in the art would clearly understand that it was not only important, but essential to Sproule's invention, for the controls to be on the console. …

In sum, the cases on which Gentry relies do not stand for the proposition that an applicant can broaden his claims to the extent that they are effectively bounded only by the prior art. Rather, they make clear that claims may be no broader than the supporting disclosure, and therefore that a narrow disclosure will limit claim breadth. Here, Sproule's disclosure unambiguously limited the location of the controls to the console. Accordingly, the district court clearly erred in finding that he was entitled to claims in which the recliner controls are not located on the console.

The summary is that is if the description makes clear that a certain element is essential, then the claims cannot be broader than that without lacking support.

A dangerous leap, in which a conclusion is reached

I would go out on a limb to say that these two principles can be combined, though I have no authority for this point.

That is, it is my opinion6 that if the description consistently disparages element X such that a broader claim would be interpreted to not include element X, then the inventor must not have been in possession of an invention involving element X. As such, a claim that is unambiguously to element X would be invalid for lacking support.

Since this relies on my opinion however, and I only play a lawyer on the anonymous Internet, you would very much be well-advised to talk to a real lawyer. They would be able to consider the facts of your situation, rather than abstract legal principles, and would be able to actually advise you.

1 Or I just missed something obvious in my search. But I prefer the other interpretation.

2 Ultimate Pointer LLC v. Nintendo Co. Ltd.

3 Many decisions have made clear is not a test, but is a way of looking at whether the inventor was in possession of the invention.

4 Hopefully this isn't a controversial statement to make. The MPEP provides a good discussion to this end with a bunch of references.

5 Gentry Gallery, Inc. v. Berkline Corp., 134 F.3d 1473, 45 USPQ2d 1498 (Fed. Cir. 1998).

6 In the sense that it's what I reckon, not in the sense that this is a formal opinion from a lawyer.

  • 1
    Interesting! At the EPO I'd be inclined to cite art 84, but for clarity, not so much for support. However, the fact that both are derived from the same article already shows how the arguments must be overlapping. In the end however, even if the claims were to be found supported - because even though the element is disparaged, it is described, the claims wouldn't be clear in light of the description. The EPO (again) would then require you to delete the disparagement from the description (or change the claims), which would however inevitably fail to comply with art. 123.
    – DonQuiKong
    May 16, 2018 at 6:21
  • And therefore, the claims can't be allowable. // Just my opinion //
    – DonQuiKong
    May 16, 2018 at 6:21
  • Okay, thanks. This sounds reasonable. In practice, one difficulty may be that the examiner is not equipped in terms of capability or perhaps even authority to make such a call.
    – user132162
    May 16, 2018 at 15:22
  • (1/2) Also, as noted in the OP edit, but which does not need to be addressed unless you feel so inclined, is a "twist" I realized after posting the question, which gets quite fact-intensive. The application of interest disparages functions 1a and 1b of embodiment 1 in the background, notes superiority of embodiment 2 in regards to at least one figure, generally refers to embodiments that don't have functions 1a/1b in the spec, but then includes a catchall including embodiment 1 and function 1a (though not explicitly function 1b).
    – user132162
    May 16, 2018 at 15:53
  • 1
    @ser132162 That twist does indeed add difficulty, and I have no view on whether that would be disavowal or not. I suspect there's no way to know until a court decides on the particular facts. Such is the unfortunate case with things which require weighing the totality of the evidence.
    – Maca
    May 16, 2018 at 20:01

Although the following case does not address the specific question, it does shed some light on claim construction at the USPTO.

In In Re Abbott (2012), as analyzed here, the USPTO was of the mind that the applicant had not disavowed disparaged scope due to an improper interpretation of Retractable Technologies, and therefore rejected claims encompassing disparaged embodiments over 102/103 (e.g. instead of 112 over lack of support):

The specification stated that the disclosed sensor overcame limitations in the prior art related to the bulk and size of prior art sensors, as well as the prior art’s reliance on external wires and cables connecting the various components that interfered with the daily life of the patient. Specifically, the specification noted that existing sensor guides “are typically bulky and do not allow for freedom of movement.

The examiner held that the broadest reasonable interpretation of “electrochemical sensor” included wires and cables, even though the specification criticized the external cables and wires of the prior art, and none of the embodiments in Abbott’s patents included external cables or wires connecting to the associated control unit.

The Board upheld the examiner during the USPTO appeal and held that, in the absence of a more express limiting statement, the broadest reasonable interpretation in light of the specification of the term “electrochemical sensor” includes wires and cables.

Having construed the term to include wires, the rejection of the claims using prior art sensors having wires was, not surprisingly, upheld. The real question remained: was the claim construction reasonable?

Abbott filed requests for rehearing, arguing to no avail that the Board improperly relied on the specification’s statement that “sensors include cables or wires. ... The Board maintained its reasoning that because nothing in Abbott’s patents explicitly disclaims sensors that include external cables or wires, the broadest reasonable interpretation of the claims should still include these features.

... the court [CAFC] emphasized that the specifications of Abbott’s patents “repeatedly, consistently, and exclusively” described sensors without wires, while simultaneously disparaging sensors with external cables or wires. Overall, based upon the findings discussed above, the Federal Circuit found the USPTO’s interpretation of “an electrochemical sensor” unreasonable.

After this guidance from the CAFC, it would be expected that the USPTO would interpret consistently disparaged embodiments to be excluded from broad claims. However, this does not answer the question of whether a claim specifically referring to the disavowed embodiments would lack support.


In support of Maca's answer, MPEP 2172 and 2174 elaborate on supported claims requiring essential elements. E.g., from MPEP 2174:

If the specification discloses that a particular feature or element is critical or essential to the practice of the invention, failure to recite or include that particular feature or element in the claims may provide a basis for a rejection based on the ground that those claims are not supported by an enabling disclosure. In re Mayhew, 527 F.2d 1229, 188 USPQ 356 (CCPA 1976).


In addition, if a claim is amended to include an invention that is not described in the application as filed, a rejection of that claim under 35 U.S.C. 112(a) or pre-AIA 35 U.S.C. 112, first paragraph, as being directed to subject matter that is not described in the specification as filed may be appropriate. In reSimon, 302 F.2d 737, 133 USPQ 524 (CCPA 1962). In Simon, which involved a reissue application containing claims to a reaction product of a composition, applicant presented claims to a reaction product of a composition comprising the subcombination A+B+C, whereas the original claims and description of the invention were directed to a composition comprising the combination A+B+C+D+E. The court found no significant support for the argument that ingredients D+E were not essential to the claimed reaction product and concluded that claims directed to the reaction product of a subcombination A+B+C were not described (35 U.S.C. 112, first paragraph) in the application as filed.

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