a) Purpose of the board's preliminary opinion 

The primary purpose of a board's preliminary opinion is to establish the framework of the appointed oral proceedings, i.e. to prepare the oral proceedings, rather than being an invitation to a party to make further submissions or to file further requests (T 2703/16, with reference to T 1459/11). See also e.g. T 752/16, T 995/18, T 2271/18.

Each party to appeal proceedings must present its own case at the outset – if necessary, by responding to the case made by the opposing party immediately – rather than waiting to see whether the board later confronts it with an unfavourable opinion (T 995/18).