5.2. Prüfungsumfang bei Änderungen

In T 866/24, during the oral proceedings before the board, the opponent (respondent) submitted that the unclear features underlying the amendments made to claim 1, which were based on the patent description, were building up on corresponding unclear formulations taken from dependent claim 6 as granted. Raising an objection under Art. 84 EPC against unclear features stemming from granted dependent claims should, in the opponent’s view, be admissible under such circumstances.

The board agreed, in principle, with the opponent's concerns. According to the board’s perception, there was a recent tendency to examine dependent claims less and less with respect to clarity in examination proceedings despite the fact that their full examination under Art. 84 EPC was not considered "unrealistic" in G 3/14, point 32 of the Reasons. Such a full examination was even expressly encouraged by the Enlarged Board in G 1/24, point 20 of the Reasons (i.e. highlighting "the importance of the examining division carrying out a high quality examination of whether a claim fulfils the clarity requirements of Article 84 EPC"). The board noted that the justification for such leniency may be found in the assumption that the protection conferred by a granted patent is defined only by the independent claims. Where dependent claims are subsequently added to an independent claim in the course of opposition proceedings, opponents are ultimately faced with unclear claim features which, as in the present case, were deemed to have been examined for clarity, although de facto they had not been. Nonetheless, they could not be objected to under Art. 84 EPC due to the conclusions of G 3/14.

The board observed that this result was unsatisfactory, as an independent claim with unclear features leaves much to the readers' imagination. It added that unclear features tend to elude a sensible comparison with the prior art. Furthermore, since opponents may not anticipate with certainty which claim construction will be adopted by the board or a court in infringement proceedings, they may feel obliged to put forward different lines of argumentation for all of the different potential interpretations. In the board’s view, categorically barring opponents in such cases from raising clarity objections under Art. 84 EPC causes undue complexities in the discussion on novelty and inventive step, to the detriment not only of opponents but also of the opposition divisions and the boards of appeal.