In T 666/90
the opposition division had indicated during oral proceedings that it would maintain the European patent as amended if new documents conforming to the version of the claims it had said it would allow were submitted. Although such a set of claims had not yet been formally submitted in writing by the applicants' representative during oral proceedings, the representative had given an undertaking to do so later and had done so by the deadline set. The written decision had revoked the patent however. The board held that this inconsistency between the oral and written decisions was in breach of R. 68(1) EPC 1973
and was hence a substantial procedural violation.