In our recent article we reported the Enlarged Board of Appeal’s decision in relation to the role of the description when assessing the claims for patentability. They concluded that, when assessing patentability, the description and drawings must always be consulted.
The importance of G 1/24 is particularly significant where there is a term in the claims and a corresponding definition in the description, which is either narrower or broader than the standard, isolated understanding of the term in the technical field. Often, during prosecution, the Examiner will cast the interpretation of a claim as broadly as possible, which captures numerous pieces of prior art. In response, the applicant may cling to a narrower definition, such as that given in the description, in order to assert that the claim is not anticipated by the prior art.
G 1/24 states that the relevant body (e.g., an Examiner) must consult the description, which may include the narrower definition on which the applicant relies, when interpreting the claims. We now have a number of decisions from the Boards of Appeal (BoA) which apply the guidance from G 1/24 and, for the most part, it has not helped patent proprietor/applicant.
T 1561/23: description consulted, but not applied
The BoA considered whether “pre-emptive tasks” disclosed in prior art fell within the scope of the claimed “additional function.” The applicant argued that the description definition of “additional function” excluded “pre-emptive tasks” based on differing runtimes. However, the BoA made clear that in their view, definitions in the description are not automatically binding for claim interpretation. It found that in this particular case, the description merely provided examples, without a clear conceptual distinction between “tasks” and “additional functions”. As a result, the claims were found to be anticipated by the prior art and, therefore, lack novelty.
T 1999/23: primacy of the claims gives legal certainty
The BoA reaffirmed that while the patent description may aid interpretation, the clear language of the claims takes precedence. In this case, the term “excitation area” in the claims had an established technical meaning – referring to the cross-sectional area of excitation light on a sample – yet the description attempted to redefine it narrowly as the area “at the focus.” The BoA found no justification for this deviation and emphasised that allowing patentees to redefine established terminology solely in the description would undermine legal certainty. The Board thus applied the established technical meaning and the claims were anticipated.
T 2027/23: no interpretive somersaults
This case centred on a joystick-controlled aerial apparatus system. The patent proprietor argued that key claim terms should be interpreted as referring specifically to electrical systems, thereby distinguishing the invention from a prior-use firefighting vehicle that employed a mechanical control system. The BoA emphasised that claim interpretation must be grounded in the claim’s clear language as understood by the skilled person, rather than narrowed by features found only in the description or specific embodiments. Where discrepancies arise between the claims and the description, it is the patentee’s responsibility to resolve them through amendment:
“…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.” (Reasons 3.5.8., T 2027/23).
This decision emphasises the emerging BoA view that if there is a scope discrepancy between the description and clear claim language, the onus is on the patentee to resolve it via amendment, rather than conceptual alignment of the meanings.
Final thoughts
The stream of decisions that we see coming out of the Boards of Appeal all point towards a common application of G 1/24: the description should always be considered, but it is rarely binding on the claimed terms. As such, it appears unlikely that patentees can rely on narrower definitions given in the description to limit the conceptual scope of the claims. Failure explicitly to include in the claims a significant term definition can prove to be fatal, even when the definition can be found in the description.
What remains to be seen is whether the Boards of Appeal will apply the same reasoning where a definition given in the description is broader that the technically established meaning. In this regard, the original BoA case, T 439/22, that made the G 1/24 referral to the Enlarged Board of Appeal will be significant. We await the outcome of that case following oral proceedings due to take place in mid-December 2025.
Phil Horler
Electronics, Computing & Physics group
Bradley Wilson
Life Sciences & Chemistry group
This publication is a general summary of the law. It should not replace legal advice tailored to your specific circumstances.
© Withers & Rogers LLP October 2025
