The EPO’s Enlarged Board of Appeal (EBA) established in decision G 1/24 that, when assessing patentability under articles 52–57 of the European Patent Convention (EPC), the claims are the starting point, while the description and drawings must be consulted to interpret the claims.
New EBA case G 1/26 seeks to clarify how this principle should be applied when assessing allowability of claim amendments.
In referring case T 873/24, the original application discloses a weight ratio >3.42 of titanium and nitrogen, whereas claim 1 as amended specifies this ratio without any units. Does the amendment contravene Article 123(2) of the EPC by adding matter?
The referring board identified three approaches in the existing case law for implementing the principles of G 1/24 when interpreting claims under Article 123(2):
The description is consulted to define the skilled person, who is then used to interpret the amended claims, only leaving out illogical or technically insensible claim interpretations;
The description is consulted to exclude claim interpretations incompatible with the technical context disclosed, and the amended claims are then interpreted without reading into the claim’s broadening or limiting features exclusively disclosed in the description; and
The patent (application) as a whole is analysed to derive how a skilled person would interpret the claims, potentially leading to broadening or limiting features being read into the claims.
Applying these approaches in the case at issue, the referring board concluded that claim 1 would contravene Article 123(2) according to approaches 1 and 2, but not according to approach 3.
The questions now pending before the EBA essentially seek to clarify which of approaches 1–3 are to apply in the future. If the referral is found admissible, the answer is of fundamental importance for users of the European patent system, as it should clarify how to apply the description in claim interpretation.
