In T 154/16 the board noted that it was the boards' established case law that the purpose of a communication from the board under Art. 15(1) RPBA 2007 was to prepare the oral proceedings; it was not an invitation to file additional submissions (with reference to Case Law of the Boards of Appeal, 9th ed. 2019, V.A.4.7.). According to the appellant (opponent), its new line of argument on inventive step, based on an additional document, was intended to bolster its existing line of attack by taking the board's preliminary opinion into account. For the board, this was not an adequate reason as it took no account of the procedural stage already reached, the potential for the other party to be taken by surprise or the fact that, if issues not previously discussed had to be dealt with at the oral proceedings, they might have to be adjourned instead of being closed with a final decision, which would be incompatible with the object of Art. 15(6) RPBA 2020. Admitting this late-filed and unexpected line of attack would run counter to both the need for procedural economy, reflected in the parties' duty to present a complete appeal case at a very early stage, and the principle of procedural fairness.
In T 102/16 the patent proprietor had filed document D26 in response to the communication under Art. 15(1) RPBA 2007 with a view to refuting the board's preliminary opinion that the prior art destroyed the novelty of the subject-matter of claim 1 according to the main request. However, the board considered that the proprietor had not put forward compelling reasons justifying filing the document at such a late stage in the proceedings. The board pointed out that it had based its communication on the objection of a lack of novelty previously raised by the opponent during both the opposition and the appeal proceedings and on which the contested decision was based. In addition, the board considered that D26's content was irrelevant for deciding on the issues of novelty and/or inventive step. It therefore refused to admit D26 (Art. 13(1) RPBA 2020 and Art. 13(1) and (3) RPBA 2007).