Technical Board of Appeal case T 2610/19 relates to an appeal from an opposition decision to maintain a patent. During the opposition hearing, the opponent was forced to select a single prior art document as closest prior art for arguing against inventiveness. This was despite the opponent expressing his intention to argue for other documents as potential closest prior art. In the interlocutory decision, the opposition board then selected a different prior art document as closest prior art.

The opponent appealed. In its decision, the Boards of Appeal confirmed that it is within the discretion of an opposition division to limit the number of inventive step attacks for discussion to maintain procedural efficiency. However, if the number of inventive step attacks is limited, a discussion about the relevance of additional prior art documents as a starting point is required to ensure that the opponent’s right to be heard is not violated.  This is particularly relevant if the opposition division considers a different prior art document as closer than the starting point(s) discussed in the oral proceedings.

The appeal board found that a procedural violation had occurred and reimbursed the appeal fee in full.