First use of G 1/24 to broaden clear claim language (T 1849/23)

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Rose Hughes

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Nov 11, 2025, 7:23:37 AM (10 days ago) Nov 11

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First use of G 1/24 to broaden clear claim language (T 1849/23)

Dr Rose Hughes Tuesday, November 11, 2025 - claim interpretation, epo, G1 24, G1/24, patents, PatKat, Rose Hughes

T 1849/23 is the first decision from the Boards of Appeal to apply G 1/24 to the use of information from the description to broaden otherwise clear claim language (many thanks to eagle-eyed Katfriend Alessandro Cossu for spotting this!). The approach of the Board of Appeal in T 1849/23 contrasts sharply with the many decisions confirming that "consulting" the description does not permit the narrowing of otherwise clear claim language. The Board of Appeal in T 1849/23 found that a broader interpretation of otherwise clear claim language could be imported from the description. The self-expressed aim of the EPO in its application of G 1/24 is legal certainty and harmonisation. Does the approach of the Board of Appeal in T 1849/23 help or hinder this?

Legal background: The G 1/24 "consultation" mandate

G 1/24 directly addressed the diverging case law on claim interpretation. In G 1/24, the EBA was asked whether the description may be consulted only if the claim is unclear and/or if it should be consulted generally. Many commentators interpreted the EBA's final order as providing clarity on this question:

"The description and drawings shall always be consulted to interpret the claims when assessing the patentability of an invention... and not only if the person skilled in the art finds a claim to be unclear or ambiguous when read in isolation".

Resisting the rotational forces

However, it quickly became apparent that what it means to "consult" the description was open to interpretation (IPKat). Following the mandatory "consultation" of the description, the question remained how the claims should be interpreted in view of conflicting definitions in the disclosure as a whole, and whether definitions and/or embodiments in the description could be ignored (IPKat) (see also the recent decision dealing with conflicting language in the claims themselves (IPKat)). Notably, the EBA chose to avoid directly addressing the issue of conflicting definitions by leaving Question 3 of G 1/24 unanswered. Question 3 asked "[m]ay a definition or similar information on a term used in the claims which is explicitly given in the description be disregarded when interpreting the claims to assess patentability and, if so, under what conditions?" The EBA felt that the answer to this question was encompassed by its answer to Question 2 that the description should always be consulted.

In this Kat's view, two questions arising from G 1/24 were therefore:

1) May otherwise clear claim language be narrowed by definitions and/or embodiments provided in the description.

2) May otherwise clear claim language be broadened by definitions and/or embodiments provided in the description.

The "no narrowing" consensus: Post-G 1/24 board of appeal decisions

Since G 1/24, we have had many decisions from the Board of Appeal finding that information in the description cannot be used to narrow the interpretation of otherwise clear claim language. See for example:

T 1561/23: "G 1/24 does not even explicitly require that the definition of a term from the description must be used for the interpretation of a claim" (r. 2.10, machine translation from the German) (IPKat).
T 2027/23: "a claim should not be interpreted, based on features set out in embodiments of an invention, as having a meaning narrower than the wording of the claim as understood by the person skilled in the art" (r. 3.5.6) (IPKat).
T 1999/23: "a restrictive definition of a term in the description may not be used to restrict the subject-matter of the claim, which would otherwise appear clearly broader to the skilled person" (IPKat)
T 1402/24: "for the purposes of judging novelty and inventive step, the description cannot be relied on to read into the claim an implicit restrictive feature not suggested by the explicit wording of the claim" (r. 2.5.2).
T 412/24: "a sensible claim construction cannot be reinterpreted on account of the description being 'consulted' or 'referred to'" (r. 3.1.1).
T 2034/23: "consultation of the description does not, however, mean that claimed features must always be construed as narrowly as any specific embodiments of the invention found in the description" (r. 3.6.2).
T 1993/23: "claim 1 of auxiliary request 1 should not be interpreted, based on embodiments presented in the description, as having a meaning narrower than the wording of the claim as understood by the person skilled in the art" (r. 3.1).
T 1819/23: The board wishes to add that, in accordance with decision G 1/24, interpreting a claim means establishing its proper technical meaning. This is distinct from reading into it limitations that are not present in its wording on the basis of the description" (r. 3.3).
T 1465/23: "these terms are not to be re-interpreted or understood in a more limited way in the light of the specific embodiments of the patent description, which, in addition, contain subject-matter that is more limited than that claimed" (r. 2.4).

It seems the Boards of Appeal are therefore very clear on the point that "consulting" the description, does not mean incorporating a narrower definition that overrides otherwise clear claim language. This consensus from the EPO is, however, currently in conflict with the UPC in Agfa v Gucci, UPC_CFI_278/2023, according to which "The definition of claimed features based on the principle that a patent may be used as its “own lexicon” is limited to those parts of the description that are related to the feature in question." (Headnote 2, IPKat). Are readers aware of any other UPC decisions that align or diverge from the EPO approach?

We have been eagerly awaiting a decision that addresses the second unanswered question, namely what is the impact of information (definitions and embodiments) in the description that may lead to a broader interpretation of otherwise clear claim language. T 1849/23 is the first case to consider this scenario.

T 1849/23 case background

The case in T 1849/23 concerned an appeal by the Opponent (Alois Kober GmbH) against the Opposition Division's decision to maintain European patent EP 3166825. The Patentee was Lippert Components Inc. The patent related to a trailer oscillation and stability control device. The invention aimed to detect and control the dangerous swaying of a trailer. Claim 1 as granted (the main request) specified a device including an accelerometer and, crucially, "an angular rate sensor (16) positioned and configured to measure rate of angular trailer deflection about a hitch pivot point (18)".

The key issue before the Board of Appeal was novelty. The Opponent argued that the prior art, which disclosed a yaw rate sensor on the trailer, anticipated the claim. The Patentee argued in response that an "absolute yaw rate" and "the rate of angular trailer deflection about the hitch pivot point" (as specified by the claim) were distinct physical quantities. In the Patentee's view, a literal reading of the claim therefore excluded a simple yaw rate sensor. The Opposition Division agreed with the Patentee in its decision, finding this feature was not disclosed in prior art.

Consulting the description to broaden the meaning of the claims

On appeal, the Board of Appeal first conceded that "when the claim is read in isolation", the Patentee's strict, literal interpretation could be justified. However, the Board of Appeal then went on to immediately note that: "in accordance with G 1/24, the description and drawings shall always be consulted to interpret the claims when assessing the patentability of an invention". Consulting the description, the Board of Appeal found that the only specific implementation of the sensor disclosed in the entire patent was a "gyroscope sensor", i.e., a sensor for measuring the yaw rate. The description itself, in the preferred embodiments, described the sensor as a "raw angular rate sensor, i.e. a sensor measuring absolute yaw rate".

The Board of Appeal found that because the patent's own description used "angular rate sensor... about a hitch pivot point" and "gyro" (yaw rate sensor) interchangeably, the claim could not be strictly construed as the Patentee submitted. The Board of Appeal thus concluded that the claim "must be construed in a broader manner" (r. 1.3). This broader construction, informed by the description, was found by the Board of Appeal to encompass the yaw rate sensor disclosed in prior art. The Board of Appeal therefore found that the device of the prior art contained all the features and that the subject-matter of granted claim 1 thus lacked novelty. The main request was therefore rejected. Nonetheless, the patent was ultimately maintained on the basis of an auxiliary request relating to a method claim, and the case was then remitted to the Opposition Division for description adaptation.

This decision can be contrasted with all of the preceding decisions finding that information in the description generally cannot be used to narrow the claims. In T 1999/23, for example, the Board of Appeal applying G 1/24 "consulted" the description, found a restrictive definition, and then promptly ignored it, giving primacy to the clear, broader claim language "to protect legal certainty" (IPKat). By contrast, in the present case, the Board of Appeal consulted the description, found a broadening implementation, and used it to override the otherwise clear, narrower claim language, leading to revocation.

Definitions versus embodiments: Does the type of information matter?

There has been some debate as to the relative impact of different forms of "information" in the description. As outlined above, the EPO refers to information, definitions and embodiments from the description that may be consulted. However, a question raised by Agfa v Gucci, UPC_CFI_278/2023 is whether there is a difference between explicit "definitions" of terms and "embodiments" of the invention described in the examples. In its reasoning, the UPC Local Division rejected "broadening" information from the embodiments but found that a narrowing "definition" did limit the claims. It has been argued that the UPC may still be open to accepting interpretations based on broadening definitions versus embodiments. However, in its Headnotes, the Local Division found that "Specifications in the description that are not consistent with the granted claims cannot serve as a basis of a broad interpretation of a claim" (Headnote 3). Who knows whether "specifications" means just embodiments or also applies to definitions!

The clear view of the EPO is that the general prohibition against importing narrowing language from the description applies to both definitions and embodiments. As T 1561/23 notes, "G 1/24 does not even explicitly require that the definition of a term from the description must be used for the interpretation of a claim" (IPKat), whilst T 2034/23 found that "consultation of the description does not, however, mean that claimed features must always be construed as narrowly as any specific embodiments of the invention found in the description" (r.3.6.2).

In this present case, it was notable that both the entire description was found to support the broader interpretation, and that the only disclosed embodiments also supported the broader definition. It is possibly also important that the description and claims were not found to be directly contradictory (IPKat). We therefore still await clarity on the impact of an explicit broadening definition on claim interpretation (e.g., as in the referring case to G 1/24, T 439/22). We are also left with the question of what to do with conflicting information in the description itself, e.g., a broadening embodiment that contradicts a narrowing definition.

Legal harmonisation and preventing the patentee from having their cake and eating it

The Boards of Appeal have cited legal certainty as a reason for not incorporating narrowing definitions from the description into the claims. The EPO only considers validity, not infringement. From the EPO perspective, therefore, a broader definition will generally not be in the favour of the patentee, as it will encompass more prior art for the purposes of novelty and inventive step. This was the situation both in the present case and in the case underlying the referral in G 1/24. By contrast, in infringement proceedings, broader definitions will generally be in the patentee's favour.

The aim of the Boards of Appeal has been explicitly stated to be to prevent the patentee having their cake and eating it on claim interpretation. In T 2027/23, for example, the Board of Appeal took pains to note that it would be highly undesirable for legal certainty to allow a patentee a narrow interpretation for validity, and then to allow the patentee to argue for a broader scope of protection when enforcing the patent (r. 3.5.4). This is probably also the reason that the EPO is prepared to accept incorporation of broader interpretations for otherwise clear claim language from the description for the purposes of validity. The EPO wishes to prevent a disconnect between claim interpretation as assessed by the EPO and the scope of the claims as determined by courts. However, it could be argued that we already have such a disconnect in cases of infringement by equivalence (Article 69 EPC). Additionally, the courts will also often consider validity, and have already diverged from the now established EPO approach to narrowing definitions.

Final thoughts

Taking a step back, the practical lesson from T 1849/23 is the same as this Kat has previously highlighted with respect to the issues surrounding G 1/24 (IPKat). As illustrated in T 2027/23, the view of the EPO is that "Patentees are the 'masters of their fate' and it falls upon them to remedy any discrepancies between the description and the claims" (r. 3.5.2) (IPKat). As such, not only should patent drafters avoid unnecessary broadening definitions, they must also be careful that their specific examples do not inadvertently broaden their carefully crafted claim language beyond what they intended and encompass unforeseen prior art. For third parties assessing validity and freedom to operate, the job never gets any easier. The lesson from T 1849/23 is that the scope of the claims may not be as clear as it first appears, and could be considered to be significantly broader in view of language buried in the description, with a potential impact for both validity and infringement. It is also currently necessary to consider how claims may be differently interpreted by the EPO and the courts.