Silence on the part of the appellant cannot be interpreted as withdrawal of the subsidiary request for oral proceedings. A request within the meaning of Art. 116(1) EPC 1973 could only be withdrawn by a declaration to that effect (T 35/92). Silence following a communication from the opposition division, asking whether the appellant was maintaining the request for oral proceedings, can also not been interpreted as a withdrawal of that request (T 686/92). A withdrawal requires an unambiguous expression of the party's wish to withdraw (T 795/91, see also T 766/90, T 879/92).
In T 1042/07 the board stated that in the absence of anything that can be regarded as a statement of grounds of appeal, the lack of any substantive response to a notification of the inadmissibility of the appeal is considered as equivalent to an abandonment of a request for oral proceedings initially made in the notice of appeal.