R. 82(1) EPC (R. 58(4) EPC 1973) provides that the opposition division is to inform the parties of the text in which it intends to maintain the patent and invite them to state their observations within two months if they disapprove of that text. The boards of appeal have frequently addressed the issue of when it is necessary to send the parties such a communication.

In T 219/83 (OJ 1986, 211) and T 185/84 (OJ 1986, 373) the board stated that, after oral proceedings in an appeal from opposition proceedings, the parties had to be sent a communication pursuant to R. 58(4) EPC 1973 only if they could not reasonably be expected to state their observations concerning the maintenance of the European patent in the amended form definitively during the oral proceedings. This case law was confirmed in several decisions (e.g. T 75/90, T 895/90 and T 570/91).

In T 446/92 it was stated that, in a case where a duly summoned opponent was not represented at oral proceedings, the decision of the board to maintain the contested patent in amended form in accordance with a request of the patentee submitted during those proceedings could nevertheless be given orally (R. 68(1) EPC 1973; R. 111(1) EPC) at the end of the proceedings, if no new facts or evidence were dealt with during the proceedings. Under these circumstances, the application of R. 58(4) EPC 1973 could be dispensed with because the patent in suit was maintained with an amended text emanating from and approved by the patentee (see, in this respect, G 1/88, OJ 1989, 189) and, furthermore, because the opponent's deliberate decision to refrain from being represented at oral proceedings before the board was to be regarded as being tantamount to a tacit abandoning of his right to present comments pursuant to Art. 113(1) and R. 58(4) EPC 1973. In the previous decisions T 424/88, T 561/89 and T 210/90 the board did not send the parties/participants a communication pursuant to R. 58(4) EPC 1973, even though the appellants (opponents) had not attended the oral proceedings.

In T 29/16 the board held that a substantial procedural violation had occurred when the opposition division did not comply with R. 82(1) EPC, which, it stated, defined the right to be heard more particularly in the case in hand. The opponent had not been invited to comment on the text, on the basis of which the opposition division intended to maintain the patent in amended form. Therein lay a violation of the right to be heard.