1. The starting point for the discussion of this decision is the examination of claims for clarity and explicitness in the granting procedure. For European patents, this is based on Art. 84 Sentence 2 EPC [European Patent Convention]. Under national law, this requirement is based on § 34 (3) No. 3 PatG [Patentgesetz = Patent Act] in conjunction with § 9 (6) PatV [Patentverordunung = Patent Regulation] (cf. BGH GRUR 2012, 475, no. 29 – “Elektronenstrahltherapiesystem” and the “Fugenband decision”, Text no. 31).
2. A lack of clarity is not a ground for opposition under the EPC and is not a ground for nullity under national law. Thus the question is how to handle “unclear claims”, e.g. in an action for nullity. It would appear that the BGH has addressed this matter in its “Proxyserversystem” decision, GRUR 2010, 709. There, in Auxiliary Request II, an additional feature was included, which was apparently taken from the description (nos. 54 + 55). The BGH denied the auxiliary request based on the lack of clarity of the newly added feature and stated in the headnote that a European patent cannot be defended in an action for nullity with patent claims that do not satisfy the requirement that the wording of a claim must be explicit, clear and concise.
3. In the “Fugenband” case, a feature already contained in the granted claims was to be ex-amined for a lack of clarity. The BGH refused to do so and stated: Neither the European Patent Convention nor the German Patent Act requires an examination of already granted claims for clarity. With a patent, which has been granted or amended in opposition proceedings, the patent proprietor has received a legal position of which the proprietor can only be deprived, in whole or part, in the cases provided for by law, i.e. if there is a ground for opposition or nullity. The European Patent Convention and national law exhaustively govern the grounds for opposition and nullity, which do not include a lack of clarity. It follows that an examination for clarity is not permitted if the presumed lack of clarity was already contained in the granted claims.
4. For the rationale for this conclusion, the BGH makes reference to the decision of the En-larged Board of Appeal in G 3/14. However, the “Proxyserversystem” decision is not cited in the “Fugenband” decision. We must still wait to see whether the BGH also adopts the decision of the Enlarged Board of Appeal when the lack of clarity of an auxiliary request is based precisely on additional features that were not examined in the granting procedure.
