19/06/2025
Yesterday, on 18 June 2025, the EPO Enlarged Board of Appeal published their eagerly anticipated decision on referral G1/24. This case considers the fundamental question of how the EPO should handle claim interpretation and the role that the description has to play when interpreting claims. As noted in the headnote provided by the Enlarged Board, the key takeaway from the decision is 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.”
Case Background
The G1/24 referral arose from an appeal of a decision of the Opposition Division relating to European patent EP3076804, titled “Heated Aerosol Generating Article with Thermal Spreading Wrap”.
The case involved the rather interesting situation whereby the description of the patent allegedly gave a broader definition to a term (a “gathered sheet”) than had been argued would typically be understood of the term by the skilled person. The view of the Board at appeal was that under the narrow definition, claim 1 of the patent would be novel, but under the broader definition given by the description, claim 1 would lack novelty.
The broad question that the referring Board in the appeal had to consider was whether the claim should be interpreted in isolation from the description (and thus, using the narrow, “common general knowledge” definition), or whether it should be interpreted in light of the broad definition given in the description. Either reading of the claims was considered clear.
The Appeal Board identified diverging case law on this matter, with one line of case law arguing that the description and drawings should only be referred to if the claims themselves are unclear or ambiguous when read in isolation. Another line of case law saying that the description and drawings should always be consulted.
Questions Referred to Enlarged Board
Three questions were referred to the Enlarged Board, the first dealing with the legal basis in the European Patent Convention (EPC) for claim interpretation, the second essentially asking which of these two lines of reasoning should be followed, and the third being a more specific questions about whether a definition of a term in the description can be disregarded when interpreting the claims.
Enlarged Board’s Decision
The answer to the first question is interesting from a legal point of view, as the Enlarged Board note that there is no single, well defined basis in the EPC for how the claims should be interpreted, with the decision stating: “The Enlarged Board considers that neither Article 69 EPC and Article 1 of the Protocol, nor Article 84 EPC are entirely satisfactory as a basis for claim interpretation when assessing patentability.” Nevertheless, the Enlarged Board considers that the case law of the EPC generally fills in this gap, with the exception of the divergence as to how the description and drawings play into claim interpretation.
This divergence is dealt with in the Enlarged Board’s answer to the second question. As referenced above in the headnote, the Enlarged Board decided that the description should always be taken into account, not just if there is an ambiguity in the claims. In coming to this decision, the Enlarged Board took the view that while Art. 69 EPC is not itself the only basis for claim interpretation in the EPC, the claims should not be interpreted in a manner contrary to it.
In particular, Art. 69 EPC states that the description and drawings shall be taken into account in determining the extent of protection. The Enlarged Board note that while Art. 69 EPC generally relates to post grant infringement proceedings, it would be undesirable for the EPO to take a different approach to claim interpretation than national courts and the UPC.
The third and final question was deemed inadmissible because the Enlarged Board considered it answered by their answer to the second question. This would seem to be an implicit “no” to the question of whether a definition of a term in the description can be disregarded when interpreting the claims, as the answer to the second question requires the description to always be consulted.
Impact on EPO Practice
This decision will no doubt have a wide impact on practice before the EPO, in some cases benefitting applicants and in other cases not. Hopefully, however, there will now be a more consistent approach to claim interpretation during both examination and opposition proceedings.
When it comes to interpreting claims during examination before the EPO, this decision may have a positive effect for applicants. EPO examiners frequently give claim terms very broad meanings when assessing claims, beyond that intended by the applicant. EPO examiners also often raise clarity objections to terms not being suitably defined in the claims. If an applicant argues back referencing the description, they are typically met with the response that the claims must be clear and interpreted without reference to the description. Now that this line of reasoning has been rejected by the Enlarged Board, and who say that examiners must refer to the description when interpreting the claims, this should lead to a reduction in these types of objections.
On the other hand, a related hot topic at the EPO at the moment is that of description amendments. Recently, the EPO have been becoming stricter on the requirement to amend the description to “conform to the claims”, meaning that any subject matter falling outside the scope of the claims in the description must be either deleted or explicitly disclaimed.
At first glance, this decision may appear to support this requirement. After all, if the description must always be referred to when interpreting the claims, then it is even more important that the description conforms to the claims, no?
It is perhaps not as simple as this, however. As set out by Article 84 EPC, it is still the claims that define the scope of protection, not the description. The description is assigned the subordinate role of “supporting” the claims. This is in line with the present decision, which requires that description is used to help interpret what is recited in the claims. For example, this may be by providing the definition of a term. Nothing in this decision should require that the description only be limited to discussing claim embodiments, as it does not say that the description supersedes the claims, such as by requiring features discussed in the description but not claimed to be “read into” the claims.
Furthermore, this decision perhaps increases the risk associated with making drastic changes to the description. By requiring that the description be used to interpret the claims, this decision makes it far more likely that changes to the description, even those which at first glance may appear unrelated to the claimed embodiments, will lead to a change in the interpretation of the claims and may thus inadvertently introduce added subject matter (while the decision only directly discusses interpreting the claims for patentability purposes, it seems difficult to imagine the EPO taking a different approach to interpreting the claims for the purposes of added subject matter). This could prove fatal to a patent if such added subject matter is found after grant during opposition or court proceedings.
In opposition proceedings, this decision should hopefully save applicants time and money during the written phase, as well as on the day, by eliminating frequent arguments around how terms should be interpreted and whether the description can or cannot be referred to when interpreting the claims. The diverging lines of case law have made such arguments common, with both sides able to cited previous cases in support of their arguments. On the other hand, perhaps more time may now be required analysing the description and how this could impact the interpretation of the claims.
Furthermore, this decision supports the potential line of attack hinted at above whereby description amendments required during examination introduce added subject matter by changing the interpretation of the claims. Such attacks have been made before, but now with clear confirmation that the description must be used to interpret the claims, they will likely be more common.
Conclusion
Overall, this decision is likely a positive development in European patent practice at least in that it should lead to a more consistent and predictable approach to claim interpretation. The benefits of more consistency will be felt across the board and hopefully outweigh the potential disadvantages for applicants that this decision may have on a case by case basis, though if this case is (mis)used to provide further support for the requirement for extensive amendments then this will not be considered a positive development by the majority of applicants.
It should also lead to a reduction in some of the seemingly more absurd decisions that come out of the EPO, such as the cases of patents being revoked through missed commas (T1473/19 and T1127/16). In both cases, had the description been used to interpret the claims, the patents may well have survived!
This article is for general information only. Its content is not a statement of the law on any subject and does not constitute advice. Please contact Reddie & Grose LLP for advice before taking any action in reliance on it.
