In T 873/24 (Board of Appeal 3.3.05, oral proceedings 3 February 2026), the Board indicated that it would refer questions to the Enlarged Board of Appeal (EBA) on whether (and how) the Enlarged Board’s claim-interpretation guidance in G 1/24 extends to the assessment of added subject-matter under Article 123(2) EPC (and, by implication, Article 76(1) EPC). The matter is procedurally significant because disputes about “what the claim means” frequently sit at the heart of added-matter objections.
Note: At the time of writing, the Board’s written decision and the final wording of the referred questions do not appear to be publicly available; the discussion below is therefore based on the publicly reported minutes of the oral proceedings and contemporaneous practitioner reporting.
Background
The appeal concerns EP 3 587 104 B1, relating to aluminium-coated steel strips. A central issue was an objection under Article 100(c) EPC (and corresponding Article 123(2) EPC analysis) directed to a compositional parameter: claim 1 included a feature that the ratio of titanium to nitrogen is “in excess of 3.42”, without expressly stating the basis of the ratio. The proprietor relied on the application as filed (and related earlier filings) indicating that relevant compositional quantities were expressed by weight, arguing that the skilled person would understand the ratio accordingly when reading the claim in context.
Key findings indicated in the oral proceedings
According to the reporting, the Board considered that the outcome turned on claim interpretation: whether the ratio feature, read as a claim feature on its own terms, was limited to a weight ratio, or whether—once the description was consulted—it should be read more broadly as encompassing other ratio bases (e.g. molar) or, conversely, should be “fixed” to the intended meaning.
The Board identified a potential tension with G 1/24, which held (in the context of patentability under Articles 52 to 57 EPC) that the description and drawings shall always be consulted to interpret the claims, not only when the claim is unclear or ambiguous when read in isolation.
A further strand of relevant case law cited in the reporting is T 405/24, which cautioned against using “consultation” of the description as a route to an interpretation that would necessarily avoid an Article 123(2) EPC objection, on the basis that such an approach risks undermining the objective nature of the added-matter test and legal certainty.
On that basis, the Board reportedly concluded that the issue raised a point of law of fundamental importance and announced that the case would be referred to the EBA, with the questions to be formulated in writing.
Analysis and implications (grounded in what is reported)
If confirmed in the written referral, T 873/24 would frame—at EBA level—the relationship between (i) interpretative principles for claims and (ii) the “gold standard” for added subject-matter (direct and unambiguous disclosure). The practical significance is that added-matter disputes often depend on whether a contested claim term is assessed on its face or in light of the description, especially where a parameter is stated without an explicit basis, unit, or definition.
Until the referral text is published, the precise scope of the questions remains uncertain. What can be said, based on the reporting, is that the Board treated the applicability of G 1/24 beyond Articles 52–57 EPC as decisive for resolving the added-matter objection in the case before it.
Conclusion
T 873/24 (Board 3.3.05) is reported as an impending EBA referral addressing whether the mandatory consultation of the description and drawings for claim interpretation established in G 1/24 should influence—if at all—the assessment of added subject-matter under Article 123(2) EPC (and potentially Article 76(1) EPC). The written referral will determine the legal question’s framing and, consequently, its practical reach.
