It already became apparent in early decisions that the boards do admit amended requests or auxiliary requests in appeal proceedings because they are serious attempts at overcoming objections, or if their late filing can be justified and admitting them does not involve the board or the other party, as the case may be, in an examination which would significantly delay the proceedings. However, requests filed shortly before or during oral proceedings, in particular, may be refused if they are not clearly allowable (T 95/83, OJ 1985, 75; T 153/85, OJ 1988, 1; T 406/86, OJ 1989, 302; T 295/87, OJ 1990, 470; T 381/87, OJ 1990, 213; T 831/92).

In other decisions too, the boards have observed that, when exercising their discretion, they must weigh up all the circumstances of the case. The later the claims are submitted, the stricter the criteria to be applied. The subject-matter of the new claims should not diverge considerably from the claims already filed, in particular they should not contain subject matter which has not previously been claimed. The new claims should be clearly allowable in the sense that they do not introduce new objections under the EPC and overcome all outstanding objections under the EPC (T 1126/97, T 52/99, T 468/99, T 397/01, T 411/02, T 81/03, T 989/03, T 515/06).

New requests may exceptionally be admitted for reasons of procedural economy, even where not filed until a very late stage (e.g. during the oral proceedings), if the amendments are justified, e.g. where filed in response to objections or comments which were not part contained in the decision under appeal but were raised in writing during the appeal proceedings and moreover do not extend the scope of discussion as determined by the decision under appeal and the statement of grounds of appeal (T 1126/97, T 52/99, T 468/99, T 397/01, T 846/04, T 1109/05).

With regard to the proper exercise of discretion in deciding whether to admit requests filed by the appellant patentee which were not submitted before the opposition division, the crucial questions to be considered are whether or not the amended claims of those requests are clearly allowable, whether they give rise to new objections, whether or not there is proper justification for their late filing (so as to forestall tactical abuse) and whether the board can deal with them without undue procedural delay (T 153/85, OJ 1988, 1; T 206/93; T 396/97; T 196/00; T 50/02; T 455/03; T 1333/05).

It is settled case law that an appellant patentee who has lost before the opposition division thus has the right to have the rejected requests reconsidered by the appeal board or to file new requests at a timely stage of the appeal proceedings, in particular together with the statement of grounds of appeal or the reply. However, if the patentee wants other (further) requests to be considered, the admission of these requests is a matter for the board's discretion, and not a matter of right (T 840/93, OJ 1996, 335; T 427/99; T 50/02; T 455/03; T 651/03; T 240/04; T 339/06).

Thus, in addition to the factors referred to in Art. 13(1) RPBA 2007, the following criteria may, according to settled case law, likewise be decisive: there must be sound reasons for filing a request at a late stage in the proceedings, as may be the case where amendments are occasioned by developments during the proceedings or where the request addresses still outstanding objections. The amendments must be prima facie clearly allowable, and their introduction must not constitute an abuse of procedure. They must not extend the scope of discussion determined by the grounds of appeal and the respondent's reply or introduce new facts on which the other party has had no opportunity to comment. Nor may they lead to an excessive delay in the proceedings. The time at which requests comprising amended claims were filed and the number of amended claim sets are also factors to be considered. Besides the timing of the request, an important factor is whether the various claim versions "converge" or "diverge", in other words whether they develop and increasingly limit the subject-matter of the independent claim of a main request in the same direction and/or in the direction of a single inventive idea, or whether they entail different lines of development because, for instance, they each incorporate different features. The scope of the amendment and the degree of difficulty or complexity involved in examining it are relevant, while the request's chances of success may also be important (see, on the last point, T 951/91, OJ 1995, 202; T 81/03; T 942/05; T 1474/06; T 162/09; T 1634/09; T 376/10; T 683/10; T 484/11; T 409/12).