The Enlarged Board of Appeal in G 12/91 (OJ 1994, 285) distinguished between decisions taken after the closure of the debate in oral proceedings and decisions taken following written proceedings. Where oral proceedings are held, the decision may be given orally. The decision becomes effective by virtue of its being pronounced. The equivalent of that point in time in written proceedings is the moment the decision is notified. Once it has been pronounced and, in the case of written proceedings, notified, the decision enters into force and cannot be amended, even by the department that issued it. A decision may only be revoked by the department that issued it by way of an interlocutory revision under Art. 109 EPC 1973 if one of the parties has filed an admissible and well-founded appeal.