In G 3/08 date: 2010-05-12 (OJ 2011, 10) the Enlarged Board found that the terms "different/abweichende/divergentes" decisions in Art. 112(1)(b) EPC had to be interpreted in the light of the provision's object and purpose according to Art. 31 of the Vienna Convention on the Law of Treaties. The purpose of the presidential referral right under Art. 112(1)(b) EPC is to establish uniformity of law within the European patent system. Having regard to this purpose, the notion "different decisions" has to be understood restrictively in the sense of "conflicting decisions". Legal development is an additional factor which must be carefully considered. Development of the law is an essential aspect of its application and inherent in all judicial activity. Consequently, legal development as such cannot on its own form the basis for a referral, because case law does not always develop in linear fashion, and earlier approaches may be abandoned or modified.

Legal rulings are characterised not by their verdicts, but by their grounds. The Enlarged Board of Appeal may thus take obiter dicta into account in examining whether two decisions satisfy the requirements of Art. 112(1)(b) EPC (see also G 3/93, OJ 1995, 18).

In G 4/98 (OJ 2001, 131) the Enlarged Board held that a discrepancy between Office practice of the EPO and the case law of the boards of appeal was not in itself sufficient to justify a referral by the President, if the practice of the EPO was not warranted by the case law.

In G 3/95 (OJ 1996, 169) the Enlarged Board considered the President's referral inadmissible due to the absence of different, i.e. conflicting decisions. In G 3/08 date: 2010-05-12 (concerning Art. 52(2) EPC, computer programs), the Enlarged Board said that T 424/03 indeed deviated from T 1173/97, but that this was a legitimate development of the case law and that there was no divergence which would make the referral admissible.

In T 646/13 the board, with reference to G 3/08 date: 2010-05-12, rejected the request for a referal to the Enlarged Board, finding that alleged contradictions between decisions T 464/05 and T 1811/13 did not exist. Rather, in the board’s view, these decisions illustrated a development of the case law on a particular question.