(a) A new argument brought forward in appeal proceedings by a party which would have the effect of amending its case, even if the argument is based on evidence and facts already in the proceedings, can only be introduced into the proceedings at the discretion of the Board of Appeal by way of an amendment under Article 13 RPBA (Point 37(a) of the Reasons).

(b) To the extent that the decision of the Enlarged Board of Appeal in G 4/92 deals with the general admissibility of new arguments in appeal proceedings, it must be taken to have been modified in accordance with (a) above by the amendments to the RPBA introduced with effect from 1 May 2003 (Point 37(b) of the Reasons).

(c) Article 13(2) RPBA must be read subject to Article 15(3) RPBA, with the result that the absence of a duly summoned party does not prevent a Board from allowing an amendment to another party's case and reaching a decision on the basis of the amended case. The absence of the party is nevertheless a factor to be taken into account in the exercise of the discretion (Points 43 and 44 of the Reasons).