The case law of the boards of appeal was reviewed in T 922/05 and much of it found to take a relatively lenient position in the sense that the appeals were deemed to be admissible if the competent board was able to infer from the particulars of the case the presumed intentions of the applicant and the probable reasons underlying its actions (see T 563/91, T 574/91, T 162/97, T 729/90). However, excessive leniency towards one party would rightly be perceived as an injustice towards the other. The board was of the opinion that submissions of a party which only made it possible for a board to infer a line of argumentation did not fulfil the requirements of either the "clear reasons" or the "express specification of facts and arguments" as prescribed by the RPBA. The statement of the grounds of appeal filed by the appellant remained silent on at least two issues, which would have been clearly relevant for deciding on the appeal, and therefore should have been addressed by the grounds of appeal in order to be complete. The silence of the appellant on these issues was seen by the board as a serious defect of the appeal. This was not changed by the fact that both issues could have been easily dispensed with in just a few sentences, without lengthy argumentation. The appeal was rejected as inadmissible (see also e.g. T 760/08, T 727/09, T 450/13, T 460/13).

In T 450/13 the board pointed out that the statement of grounds of appeal was not sufficiently substantiated with regard to the alleged public prior use attacks. A reference back to first instance proceedings was not a sufficient reasoning to render a submission in the statement of grounds of appeal admissible (see T 473/09). The submissions in the statement of grounds of appeal had to be such as to enable the board (and any other party) to understand immediately why the decision was alleged to be incorrect, without first having to make investigations on its own. To ask the board to do this would mean that the board had to make up the appellant's case in breach of the principle of impartiality (see also T 1676/08).