EPO: Uniform Claim Construction and the Limits of Using the Description

In this decision, the Board of Appeal addresses the principles of uniform claim construction, drawing on the landmark decision G 1/24 of the Enlarged Board of Appeal of the European Patent Office. The description and drawings must be used to interpret the patent claims not only when assessing patentability (Articles 52 to 57 of the European Patent Convention), as recently stated in decision G 1/24 of the Enlarged Board of Appeal, but also when examining all other requirements of the European Patent Convention (EPC). Patent claims must always be interpreted consistently and uniformly when examining compliance with the EPC. However, if claims were to be mentally restricted on the basis of the description and drawings during the examination of added subject-matter, even though such restrictions cannot be derived from the literal wording of the claims themselves, this would deprive the provisions of Article 123(2) and Article 100(c) EPC of their purpose and meaning. (EPO-BoA 18.02.2026, T 2488/22)