The factual bases for a review procedure under Art. 112a EPC are the minutes of the oral proceedings and the grounds for the decision under review (R 15/09, R 6/14). However, in R 3/10 the Enlarged Board also took signed declarations of persons who had attended the oral proceedings into account.

In R 4/16 the Enlarged Board stated that, according to its settled case law on petitions for review, the boards were not obliged to explicitly state the reasons underlying a decision until they issued the final decision in writing (see R 8/13 of 15 September 2015 date: 2015-09-15). R. 124(1) EPC required only that the minutes of oral proceedings contain the essentials, so they did not have to record every single point addressed at those proceedings. It therefore could not be inferred from a point's omission from the minutes that it had not been considered.