April 2026 In this case, the Board of Appeal (BOA) considered the description to have a significant influence on claim interpretation, with the potential to both narrow and broaden the scope of the claims. This raises important questions on how description amendments may negatively affect claim interpretation post grant.
Summary of T 439/22
This decision represents a further development of the earlier T 439/22 proceedings, which led to the G1/24 referral to the EPO’s Enlarged Board of Appeal (EBA). The decision of the EBA was reported in our previous article.
To recap, granted claim 1 of EP 3076804 was found to lack novelty because the BOA saw no reason to disregard an explicit definition provided in the specification, one that encompasses the prior art within the scope of the claim. This interpretation of G 1/24 illustrates that definitions in the description can be used to broaden the meaning of the claim language. In this respect, the present decision is similar to decision T1849/23, discussed here.
In an effort to avoid revocation of the main request, the Patentee submitted an auxiliary request in which the paragraph containing the problematic definition was deleted from the description.
The Opponent argued that removal of the definition from the description would alter the interpretation of the claims and broaden the claim scope. The Patentee countered that the deleted subject‑matter was already implicit in the claims.
The BOA sided with the Opponent and took an approach that diverges from previous BOA decisions. The BOA concluded that the deletion of the problematic definition would broaden the scope of the claims. The BOA further stated that “the skilled person will read terms in the claim in the sense of the definition, taking into account both the broadening and limiting aspects.” As such, it was found that the removal of the definition would therefore result in a broader scope of protection than that of the granted patent, amounting to added matter. Interestingly, the BOA in this case was willing to rely on the description to narrow claim interpretation, contrary to other BOA decisions thus far.
Take Home Messages
This case is the first to clearly demonstrate a direct connection between description amendments and added matter concerns. If the contentious paragraph had been deleted before grant to bring the description into conformity with the claims, the patent would have become vulnerable to an added matter attack, potentially leaving the Patentee trapped with no permissible amendments to restore validity as reinstating this language would impermissibly extend the scope of the granted patent (Art. 123(3) EPC), as the BOA took the view that the contentious paragraph had both narrowing and broadening effects on the claim scope.
The Board of Appeal’s reasoning further confirms the descriptions significant influence over how claims can be interpreted, potentially narrowing or broadening their scope. This raises important questions about how seemingly routine description amendments may unintentionally affect claim interpretation after grant.
