In J 5/94 it was decided that the grounds on which a request for re-establishment of rights was based could be elaborated on, provided this completed the submission that had been filed in due time and thus did not alter the basis on which the original request for re-establishment had been filed (see also J 19/05, T 585/08, J 15/10, T 592/11).

In T 324/90 (OJ 1993, 33) the board held that evidence proving the facts set out in the application could be filed after expiry of the two-month time limit laid down in Art. 122(2) EPC 1973. Only the grounds and a statement of the facts had to be filed within the two-month period. Likewise in T 261/07 the board allowed the patentee, who had initially given an account of all the relevant facts to the best of its knowledge, to subsequently adduce further clarifying evidence supporting the case.

In J 5/11 the Legal Board held that the applicant for re-establishment of rights who failed to substantiate his request adequately in the first instance proceedings, in particular after being expressly invited to do so, could not normally make good that failure by submitting additional evidence with the grounds of appeal. While it was true that the primary function of the boards was to give a judicial decision on the correctness of a first-instance decision of the Office (see J 18/98), that does not necessarily mean that new evidence submitted for the first time on appeal was automatically inadmissible. A rigid rule excluding all new evidence on appeal might lead to injustice and unfairness in some cases and would not be compatible with the principles of procedural law generally recognised in the contracting states (cf. Art. 125 EPC).

In J 18/98 the examining division had refused the applicant's application for restitutio in integrum. An appeal was filed against that decision. From the established case law on Art. 122(3) EPC 1973 the Legal Board concluded that facts submitted only with the statement of grounds of appeal could not be taken into account, since the function of appeal proceedings was only to give a judicial decision upon the correctness of an earlier decision of the department of first instance (T 34/90, OJ 1992, 454).

In T 257/07 the board stated that it had been only one year after the removal of the cause for non-compliance that the appellant qualified certain statements previously made and added new facts that previously went unmentioned, in particular regarding the system for managing files and deadlines. This omission could not be subsequently remedied by the addition of further facts, as case law would only allow the appellant to "submit further evidence which clarifies the facts which were set out in the application for re-establishment" (J 2/86, OJ 1987, 362; T 261/07; see also T 742/11, T 2274/11, J 6/14).

In J 16/11 the Legal Board pointed out that the boards of appeal had consistently ruled that facts pleaded for the first time during the appeal proceedings should in principle not be taken into consideration (see J 18/98, T 257/07). In the case at issue, the board had, by its communication, informed the appellant that the evidence currently on file did not seem convincing enough and, exceptionally, gave the appellant an opportunity to improve its case at this late stage of the proceedings. However, the representative, instead of filing evidence, produced a "sworn statement" written by the appellant himself. Given that the new submission did not complement the already existing facts, but presented a new situation, these facts and evidence had to be disregarded.