Patents
G 1/24: emerging trends in case law
September 23, 2025
Much has already been written about the Enlarged Board of Appeal's decision in G 1/24, which aimed to settle the issue of whether the description and figures must be consulted to interpret the claims of a patent when assessing patentability under Article 52 to 57 EPC. This article discusses emerging trends in the case law that has since emerged.
The order in G 1/24 stated “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.”
However, the question still remains as to whether a definition from the description or drawings should be used following the consultation, and in what circumstances. The Enlarged Board of Appeal considered a question on this topic to be inadmissible in their decision, which means there is still some uncertainty. One could consult the description and drawings and subsequently disregard their teachings when interpreting claims.
A small body of case law is starting to emerge, which appears to give some insight into the above issue.
This appeal was directed towards the refusal of patent application EP 1772035.9 after oral proceedings, which is a patent application relating to a real-time environment and programmable logic controller.
The board of appeal did consult the description in their decision. They referenced the description to explain why in their view a narrow interpretation of the term (translated) “additional function”, based on an embodiment in the description, was not warranted. The board were of the opinion that consulting the description was distinct from using any definition in the description (Reason 2.10).
Therefore, consultation of the description and drawings was undertaken, but it ultimately had little sway on how the term “additional function” was interpreted by the board. The board argued that there wasn’t strictly a “definition” within the description, but only examples of the term in questions (2.10).
The board upheld the decision in this instance.
This appeal was towards a decision of the Opposition Division to revoke patent EP 3 086 087, relating to a photo thermal measuring device.
In this decision, the Board of Appeal stated that in G 1/24 it was emphasised that existing principles developed by case law still applied. Therefore, a restrictive description definition of a term (“excitation surface”) was not to be used to limit the subject-matter of the claim (Reason 5.6). They reasoned that G 1/24 also emphasised interpretation begins with and is based on the claims (5.7).
Therefore, like in T 1561/23, the description was consulted but not used to interpret the claims.
The latest T decision to refer to G 1/24 again relates to an appeal towards an Opposition Division decision to revoke a patent. The patent in suit (EP 2 960 746) concerning a control system for controlling the movement of an “aerial apparatus”. Particularly for controlling a “turnable ladder of a firefighting vehicle”.
Again, the board disagreed with the notion that definitions given in the description should automatically be read into the claim, and that G 1/24 is silent on the purpose of such a consultation (Reason 3.5.2)
Conclusion
In all of the cases that have cited G 1/24 so far, all of the appellants have sought to use the description to support a narrowing interpretation of a claimed term. In all of the cases so far, the Boards of Appeal have rejected these narrow interpretations.
However, there are no T decisions as of yet in which a broad yet technically sensible definition within the description is used to broaden the claim scope from a commonly understood, narrower interpretation of a term in the claim. The referring T-decision (T 0439/22) that led to G 1/24 is a case like this, and the outcome will be interesting to note when it arrives.
If there is a decision in which a broader description definition is used to read on the meaning of the claim, this is potentially pointing to a larger trend towards something similar to the USPTO position of “broadest reasonable interpretation”, in which words in the claim must be given their plain meaning (understood by those of ordinary skill in the art) unless such a meaning is inconsistent with the specification.
In any case, regardless of G 1/24, applicants and drafting attorneys must remain ever cautious about any special definitions given in their descriptions. Particularly if said definitions deviate from commonly understood terms, and especially if these definitions are broader than commonly understood definitions.
Oliver McHugh
Patent Advisor