In T 344/88
the board of appeal considered whether the citing by the opponent of the wrong number for a patent specification contravened R. 55(c) EPC 1973
(now R. 76(2)(c) EPC
), if the mistake was not corrected until after expiry of the opposition period. The first patent specification cited by the opponent bore no relation at all to the invention. However, the notice of opposition contained enough detailed information for it to have been possible to identify the actual patent specification intended. The board of appeal allowed the number to be corrected. Given such a detailed submission of facts, it would have been taking formal requirements too far to reject the opposition simply because the wrong number had been given for a cited patent specification. Whether or not the EPO actually effected a correction between receipt of the notice of opposition and expiry of the period of opposition was irrelevant. The sole decisive factor was that the error was recognisable within the period for opposition and that the opposition division was able, on the basis of the description of the citation, to establish the latter's identity beyond all doubt.