The referred question must not have a merely theoretical significance for the original proceedings which would be the case if the referring board were to reach the same decision regardless of the answer to the referred question (G 3/98, OJ 2001, 62; G 2/99, OJ 2001, 83; see also T 547/08). It must be relevant for deciding the case in question (G 2/04, OJ 2005, 549; T 2136/16), or the Enlarged Board must be satisfied that "answers to the questions referred are necessary for each Board of Appeal to be able to dispose of their respective appeals on the correct legal basis" (G 1/05 date: 2007-06-28, OJ 2008, 271; G 1/06, OJ 2008, 307; see also G 2/06, OJ 2009, 306). In T 154/04 (OJ 2008, 46; see also J 16/90, OJ 1992, 260; and T 1044/07) the board held that the answer to the referred question must be "essential to reach a decision on the appeal in question".

In T 520/01 (see also T 787/06) the board referred to G 3/98, did not maintain the patent on grounds other than those to which the question related, and thus refused the party's referral request. In T 469/92, the board granted the appellant's main request, and therefore did not consider its auxiliary referral request.

In G 1/98 (OJ 2000, 111) one of the questions referred by the board concerned objections of which the appellant had not been made aware before, and the appellant expressed its intention to the Enlarged Board to make the required amendments. As a result, the Enlarged Board doubted the relevance of the referred question and deemed it inappropriate to offer guidance. In G 7/95 (OJ 1996, 626, see also G 9/92 of 22 June 1993 date: 1993-06-22) the Enlarged Board, having regard to the particular facts of the case before the referring board, deemed it not necessary to answer the referred question either.

In G 1/09 (OJ 2011, 336) a board referred a question on whether a rejected patent application was still pending under R. 25 EPC 1973 (R. 36 EPC; divisional applications) when no appeal had been filed but the time limit for filing an appeal had not yet expired. In his comments under Art. 9 RPEBA, the President of the EPO raised two additional questions, namely whether a granted application was still pending in such a situation, and whether the filing of an inadmissible appeal could maintain the pendency of the application beyond the expiry of the time limit for filing an appeal. The first additional question was – although not relevant for the decision in the underlying case – answered by the Enlarged Board in an obiter dictum, whereas the second was considered not to be covered by the referral decision.

In G 2/03 (OJ 2004, 448) the Enlarged Board stated that not all substantive requirements had been examined by the referring Board and that the referred question could, in the end, turn out to be irrelevant. Taking into account the usual order of examination according to which the referred question (on the allowability of disclaimers) was examined before substantive requirements such as inventive step, the Enlarged Board considered the referral nevertheless admissible. In G 2/99 (OJ 2001, 83), the Enlarged Board had doubts whether the answer to the referred question would have an impact on the decision in the underlying proceedings, but deemed the referral nevertheless admissible, for reasons of procedural efficiency. In G 2/07 (OJ 2012, 130) the referrals were considered admissible "irrespective of whether an answer is actually required on all aspects which the referred questions might in theory be seen as embracing".

In G 1/14 the question referred to the Enlarged Board was whether an appeal is inadmissible or deemed not to have been filed if the notice of appeal is filed and the fee for appeal paid after expiry of the time limit (see chapter V.A.9.3. "Appeal deemed not to have been filed or inadmissible appeal"). Until 1 April 2015 the wording of R. 126(1) EPC was limited to "Notification by post ... by registered letter with advice of delivery" (since amended to: "Notification by postal services ... by registered letter with advice of delivery or equivalent"). In the Enlarged Board's view notification of first-instance decisions by the postal service UPS was not covered by R. 126(1) EPC as formerly in force, so the referring board's finding that the appeal had not been lodged in time was inoperative. As this meant there was no need to refer the question, the Enlarged Board dismissed the referral as inadmissible.