We have already provided a brief summary of the recently issued decision in G1/24 which provides clear guidance on the principles of claim interpretation under the European Patent Convention (EPC). As one of the most important decisions to issue in recent years, we are now taking a deeper dive into the decision and its implications.
Background
Contrasting approaches to claim interpretation have evolved at the EPO, in particular to what extent the description should be used to interpret the claims. At one extreme, terms in claims could be interpreted in isolation, without any recourse to the description ever. At the other extreme, the whole patent application is used as its own dictionary such that the description can provide definitions for claim terms that are contrary to their normal meaning. Thus, a term in a claim that is otherwise clear may be given a broader or narrower interpretation as a result of what is disclosed in the description. There is also middle ground where the description is considered only when there is ambiguity in a claim term: all claim terms that are clear are given their normal meanings and the description is ignored. These different approaches are reflected across a wide body of case law, with the latter two approaches most often favoured.
The appeal case leading to this decision, T 0439/22, has claims that contain the term “gathered sheet” which is used to describe a tobacco sheet in an aerosol generating device. The Board took the view that “gathered sheet” was a well-known term in the technical field with an accepted meaning, but the description of the patent specification set out further definitions that were broader. So, is this a case where the description can act as its own dictionary such that the broader meaning should be given to the term “gathered sheet” when interpreting the claims?
Case law must follow the legal basis set out in the EPC, so what does the EPC have to say on claim interpretation?
An obvious place to start is Article 84 which has the heading “Claims”. This article is very short and provides no guidance on claim interpretation. The Article says, “The claims shall define the matter for which protection is sought. They shall be clear and concise and be supported by the description.” The Implementing Regulations to the EPC provide further guidance on the form of the claims, but nothing regarding claim interpretation.
Article 69 (and its associated Protocol) looks more promising in that it says the extent of protection of a granted European patent is determined by the claims, and that the description and drawings shall be used to interpret the claims. However, this Article refers to a European patent and case law diverges on whether Article 69 should also apply when considering patentability of a patent application.
As a consequence of this diverging case law, the following three questions were referred to the Enlarged Board of Appeal:
The key legal issues
The Enlarged Board of Appeal confirmed that neither Article 69 EPC (and the Protocol) nor Article 84 EPC are entirely satisfactory as legal basis for claim interpretation when assessing patentability.
The Enlarged Board noted that Article 69 EPC and the Protocol are arguably only concerned with infringement actions before national courts and the Unified Patent Court. Their conclusion was based on the wording of Article 69 EPC and the Protocol, their drafting history, and their position in the EPC.
The Enlarged Board also considered Article 84 EPC when considering question 1 above. They noted that the Article is formal in nature and that it neither mentions the invention nor provides guidance on how to interpret the claims. Referencing T 1473/19 (Reasons 3.8), the Enlarged Board stated that “[Article 84 EPC] only sets out an instruction to the drafter of what needs to be in the claims, and an instruction to the EPO to determine whether the claims meet that purpose” .
Consequently, the Enlarged Board answered question 1 in the negative, establishing that there is no legal basis within the EPC for claim interpretation when assessing patentability.
Nonetheless, the Enlarged Board found that this “does not mean that it is necessary to invent from scratch new principles of claim interpretation”. The Enlarged Board deemed that their answer to question 1 does not affect the principles that were to be applied to claim interpretation in practice. Specifically, the Enlarged Board noted that the body of case law developed by the Boards of Appeal provides guidance on this issue. From this case law, the Enlarged Board noted that the following principles could be extracted:
1) The claims are the starting point and the basis for assessing the patentability of an invention under Articles 52 to 57 EPC.
2) The description and any drawings are always referred to when interpreting the claims, and not just in the case of unclarity or ambiguity.
Whilst the first principle was considered a “settled point” by the Enlarged Board, they indicated this was not the case for the second principle because of the diverging case law.
Helpfully, this divergence in case law has been settled by the Enlarged Board’s answer to referred question 2.
The Enlarged Board rejected the case law that says the descriptions and drawings are only to be considered when a term in a claim is unclear or ambiguous. They believe that such case law “is contrary to the wording, and hence the principles, of Article 69 EPC. It is also contrary to the practice of the national courts of the EPC states and to the practice of the UPC”.
It is interesting to see this nod to the Unified Patent Court (UPC) and, as such, it appears that the Enlarged Board is particularly mindful of harmonising with the Unified Patent Court (as well as national courts). They stated that “it a most unattractive proposition that the EPO deliberately adopt a contrary practice to that of the tribunals that are downstream of its patents” . The Enlarged Board noted that their findings are compatible with the Unified Patent Court’s existing case law, citing the UPC Court of Appeal’s decision in NanoString Technologies -v- 10x Genomics.
To conclude, as set out in the order at the end of the decision, the Enlarged Board confirmed:
The claims are the starting point and the basis for assessing the patentability of an invention under Articles 52 to 57 EPC. 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.
The Enlarged Board found question 3 to be inadmissible. This is because the question relates to whether a definition of a term in the description can be disregarded when interpreting the claims and so was deemed to be encompassed by question 2.
It follows from the answer to question 2 that question 3 would be answered in the negative. Since the description must always be consulted, a term in the description should not be disregarded when interpreting the claims.
Looking forward
During proceedings it was highlighted, particularly by the EPO, that there is also uncertainty around whether the description should be amended to conform with the claims. The Board of Appeal in T 0697/22 is contemplating whether to refer questions to the Enlarged Board of Appeal on this issue.
Although the Enlarged Board did not address this matter in this decision, their finding that the description must always be considered when interpreting the claims implies that the description ought to be amended in line with the interpretation argued for the claims. In particular, the requirement for the claims to be clear is likely to be interpreted to mean that the claims must be clear in the context of the description: that is, the description must not suggest a different interpretation of the claims than has been argued, for example to establish novelty and inventive step over prior art.
This decision also has implications for drafting patent applications, particularly where text is added to the description to provide definitions for claim terms. An interesting question is if only a single definition of a claim term is provided in the description, is the applicant then stuck with that broader definition? For example, if a definition is provided in the description that broadens the normal meaning of a term in the claims, can the applicant then delete the definition and argue that the claim term should have it usual, narrower meaning or will this be deemed to add subject matter?
We always take great care when drafting patent applications and are mindful of the issues raised in this decision. We also offer a service to review patent specifications before filing with the European Patent Office directly (i.e. not PCT) to advise on how well they conform to the various requirements of the EPO. We can also suggest amendments to overcome potential issues to be made on filing while we are not bound by the EPO’s strict application of the requirement not to add subject matter. This option is not available for PCT regional phase entries where any amendments must not add subject matter over the PCT application as filed in the international phase. Hence, associates preparing PCT patent applications should be mindful of the issues raised by this decision.
The decision also has relevance when assessing third party applications and patents still within the EPO’s jurisdiction (i.e. recently granted patents still within the 9-month period for filing an opposition or with oppositions pending). However, the decision has a lesser consequence for assessing third party patents that are out of the EPO’s jurisdiction, for example when considering infringement and validity. This is because the decision effectively moves how claims are interpreted closer into alignment with how the exercise is performed by national courts and the Unified Patent Court.
Conclusion
Overall, the decision should be welcomed as it provides more certainty for all parties. There is a clear aim by the Enlarged Board to prevent inconsistencies between the extent of protection granted by the claims and how the claims should be interpreted for determining patentability.
With this important decision, we expect there to be updates to the EPO Guidelines for Examination. It will be interesting to see if the revisions cover just claim interpretation or whether they also cover amendments to the description. The next update to the Guidelines is expected to be in 2026, of which we will report on separately.
Please contact your regular Boult contact if you have any questions regarding how G1/24 could impact your patent needs.
The full decision can be found here.
