Interpreting Claims After G 1/24: Emerging Trends from the Boards of Appeal

Following the decision of the Enlarged Board of Appeal (EBA) in G 1/24, the Board of Appeal has now applied the EBA’s decision in the referring case, T 0439/22. As a recap, the questions referred to the EBA in G 1/24 could be summarised as: when should the description be used to interpret the claims?

In our previous article, we explained that in G 1/24, the EBA concluded that “the description and drawings shall always be consulted to interpret the claims when assessing the patentability of an invention under Articles 52 to 57 EPC, and not only if the person skilled in the art finds a claim to be unclear or ambiguous when read in isolation” (emphasis added). As well as the referring case, a number of other recent decisions have also now cited G 1/24, and in this article, we provide a brief overview of how Boards of Appeal are beginning to interpret and apply the G 1/24 decision.

The first decision from the Boards of Appeal to cite G 1/24 was T 1561/23; in this case the Board interpreted G 1/24’s guidance as “not explicitly requiring that the definition of a term from the description must be used for the interpretation of a claim”, rather that the description only needs to be consulted. However, a number of subsequent cases to cite G 1/24 place much more emphasis on always using the description to interpret the claims. 

In principle, where the description contains a definition of a term in a claim, that definition may either broaden or narrow the interpretation of the term in the claim as compared to the ‘normal’ meaning in the art. As explained in more detail below, differing outcomes have arisen depending on whether the description contains a broadening or a narrowing definition. Further to this, Boards have assessed the effect of a more narrowly defined embodiment in the description, and whether that has an effect on the interpretation of the claims.

Description alleged to have a narrowing effect
In T 1999/23, claim 1 specified a device comprising a light source for heating a sample and an infrared detector to detect thermal radiation from that heated sample. A requirement of claim 1 was that the light source was an LED having an “excitation area” of a specified size. The normal meaning of “excitation area” was at odds with the definition in the description, which gave an unusually restrictive meaning to the term. The skilled person, without consulting the description, would therefore be expected to interpret the claim more broadly. The Board of Appeal commented that the EBA in G 1/24 made it clear that a principle developed by case law which should be followed is “that a restrictive definition of the term in the description may not be used to limit the subject matter of the claim, which is otherwise clearly broader for the skilled person” (machine translation from German). The Board of Appeal in this case concluded that there was no good reason to depart from the clear technical terminology of the claim term; the description should be consulted, but a definition in the description should not override clear claim language. Ambiguity had therefore been created due to the inconsistent use of the term “excitation area”, and the patent was subsequently revoked for lack of novelty over the novelty-only prior art document.

In T 1465/23, the Board “consulted” and “referred to” the description and drawings to inform them on defining the skilled person and thus how to interpret the claims. It was reasoned that, based on the skilled person being familiar with the “stable and well-understood meaning” of the terms in the claim, the normal meaning of the claims was broader than the more restrictive description. The Board concluded that terms in the claims “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.” This case can be seen to firmly state that the content of the description does not necessarily give the claims a narrower meaning than would be understood from reading the claims in isolation.

Further to this, the case T 2027/23 concerned novelty of the claims under Article 54 EPC in light of public prior use. The patent in question related to a control system for a firefighting vehicle. The Patentee’s argument centred on asserting a narrower meaning of the claim language based on an embodiment in the description, limiting specific terms to electrical systems which would give them novelty over the public prior use vehicle. The decision in 
T 2027/23 states that “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. In cases of discrepancy between the claim language and the description, it falls upon the patentee to remedy this incongruence by amending the claim. It is not the task of the Boards of Appeal to reach such alignment by way of interpretative somersaults”. The Board resolved that the claims have primacy and therefore rejected the Patentee’s arguments and the patent was revoked.

These three example cases therefore point towards Boards of Appeal, when faced with a description that purportedly narrows a well-understood term in a claim, falling on the side of the claim not being narrowed in scope by the description. This trend is neatly summarised in
T 1819/23, where the Board “wishe[d] to add that, in accordance with the 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”. However, there are subtleties to note depending on whether the narrowing language in the description is a narrowing definition of a term or is a narrowing embodiment of the invention. Further, it is worth noting that recent UPC decision Agfa v Gucci (UPC_CFI_278/2023) contrasts this approach, concluding that a narrowing definition in the description should be used for interpreting the claims. 

Description alleged to have a broadening effect
In contrast to the above ‘narrowing’ cases, T 1849/23 was the first decision of its kind following G 1/24 where a broadening definition in the description was found to give an expanded meaning to otherwise clear claim language. The Board of Appeal overturned the Opposition Division’s decision, concluding that although the claims could be seen to be novel when read in isolation, when read in tandem with the description in accordance with G 1/24 the claim had a broad meaning that encompassed subject matter disclosed in the prior art. More particularly, the Board concluded that, in light of G 1/24, the claim “must be construed in a broader manner”. The yaw rate sensor disclosed in the prior art was found to be disclosed in claim 1 of the patent in question and thus claim 1 was found to lack novelty.

As mentioned previously, the Board of Appeal decision for T 0439/22, the referring case for 
G 1/24, has now been issued and is the second case to find that a broadening definition in the description broadens the scope of the claims. Here, the Board of Appeal confirmed that the description must be consulted to interpret the claim, and thus claim 1 was not novel in light of the prior art. The Board stressed that interpretation of the claims should be done as a ‘holistic’ exercise whereby the description and claims are consulted in parallel. It is also noteworthy that an auxiliary request submitted by the patent proprietor to remove the definition of the “gathered sheet” from the description was not allowed. Specifically, the Board stated that the request would contravene Article 123(3) EPC and thus would extend the protection conferred by the patent. The Board explained that “as long as the definition is technically reasonable and complies with the overall teaching expressed in the claims, description and figures, the skilled person will read terms in the claim in the sense of the definition, taking into account both the broadening and limiting aspects”. Following that reason, the Board concluded that, in deleting the definition, the limiting aspects of that definition were also omitted leading to a different claim scope as compared to the patent as granted. Thus, the auxiliary request was denied and the patent was revoked.

From these decisions it appears that the Boards of Appeal are taking a different direction when the description broadens the scope of the claims. In these cases, Boards of Appeal have so far assessed patentability on the basis of the broader meaning given in the description, in contrast to cases where the description was found not to place a narrowing limitation on the claims.

G 1/24 is provoking further debate
A recent case, T 873/24, has opened the floor for further discussion hinging on the G 1/24 decision. The Board of Appeal has referred questions to the EBA concerning whether the description should be consulted when interpreting the claims in instances of assessing added matter under Article 100(c) and Article 123(2) EPC. The referred case concerns the omission of units in claim 1 of the main request, which is considered to add matter over the application as filed. The Patentee in the case has argued that, in light of G 1/24, the description must always be considered when interpreting the claims and therefore there would be no confusion over how claim 1 should be interpreted. The Opponent has countered that, when considering the decision of T 0405/24, G 1/24 should not be used for the assessment of added matter under Article 123(2) EPC. However, the Board in T 873/23 stated that the findings of G 1/24 are considered to “be true not only for the question of “patentability of an invention under Articles 52 to 57” but also for the issue of Article 123(2) EPC”. 

In light of this referral, it certainly appears that G 1/24 has not only prompted much thought when assessing patentability, but it has also opened the door for further debate and clarification on the use of the description to settle issues around added matter. It will be interesting to follow this referral and to see whether the EBA considers it to be admissible.

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