An inconsistency between the oral decision announced at the oral proceedings and the written decision is in breach of R. 111 EPC (formerly R. 68(1) EPC 1973) and is hence a substantial procedural violation (see e.g. T 666/90). In this decision the opposition division had indicated in oral proceedings that it would maintain the patent as amended on submission of new claims (which were submitted by the deadline set) but in its written decision revoked the patent. Similarly, in T 425/97 the sole ground of appeal was the inconsistency existing between the written decision and the form of the patent held to be patentable by the opposition division at the oral proceedings. The substantive deviation amounted to a procedural violation. See also T 318/01, T 1590/06 and T 1698/06.
In examination proceedings, where the decision to grant the patent referred to the documents approved by the applicant under R. 51(4) EPC 1973 (now R. 71(3) EPC) these documents became an integral part of that decision (see T 850/95, OJ 1997, 152). In T 740/00 the board found by analogy, that in opposition proceedings the documents referred to in the decision to maintain the patent in amended form also formed an integral part of that decision. Differences between the decision pronounced at the oral proceedings and the written decision were not mistakes which could be corrected under R. 89 EPC 1973, but amounted to a substantial procedural violation requiring immediate remittal of the case to the department of first instance.