In T 1028/96 of 15 September 1999 date: 1999-09-15 (OJ 2000, 475) the board stated that, in addition to the two admissibility conditions prescribed in Art. 24(3) EPC, the EPC required, as a general rule, that objections be reasoned, i.e. indicated facts and arguments which were alleged to support such an objection. From this requirement it followed, firstly, that an objection based on purely subjective unreasonable doubts should be rejected as inadmissible. It also followed that if facts and arguments filed could not support the objection of suspected partiality raised, the objection was likewise inadmissible (see also T 355/13).

In R 12/09 of 3 December 2009 date: 2009-12-03 the Enlarged Board of Appeal referred to T 1028/96 date: 1999-09-15 and also held that, when determining admissibility, it had to be established whether the objection had been duly substantiated. However, according to the Enlarged Board, this merely meant ascertaining whether it met the minimum standard for objective reasoning, and not whether that reasoning was also persuasive.