See also chapter V.A.5.12.14 "Reverting to broader claims, especially those as granted".
Established case law of the boards of appeal has it that previous limitations of the claims cannot be treated as an express abandonment of parts of the patent but are to be regarded merely as attempts to come up with a wording delimiting the patent in such a way as to overcome objections. The patent proprietor is free at any time to revert to broader claims or to the version as granted, provided this does not amount to an abuse of procedural law (T 43/16; see T 123/85, OJ 1989, 336; T 296/87, OJ 1990, 195; T 900/94; T 1018/02; T 934/02; T 699/00; T 794/02). Nonetheless, the admissibility of any such request on appeal is subject to the provisions of Art. 12(4) RPBA 2020 (see T 28/10, T 1135/15).
According to T 123/85 (OJ 1989, 336), the EPC makes no provision for patentees to surrender their patents during opposition proceedings (referring to T 73/84, OJ 1985, 241; T 186/84, OJ 1986, 79) nor surrender part of the patent so as to limit it. Thus a request withdrawn during opposition proceedings may nonetheless be considered in any ensuing opposition appeal proceedings.
In T 1018/02, it was stated that amendments of a European patent had to comply with R. 57a EPC 1973 (R. 80 EPC). According to this rule, amendments were possible provided that they were occasioned by grounds for opposition. However, this did not mean that, if a patent proprietor in the first instance chose to defend a main request which was limited in scope compared with the claims as granted, then he could not during the appeal proceedings go beyond the limits of that request. In accordance with T 407/02, a patent proprietor who had only defended his patent in limited form before an opposition division, was in principle allowed on appeal to return to a broader version or even to the patent as granted. Following T 407/02, the board in T 1188/09 pointed out that opponents must therefore always be prepared for the possibility that a patent proprietor whose patent has been revoked by the opposition division will seek its restoration as granted on appeal. According to the board in T 1188/09, T 1018/02 expressly followed this approach, which was again upheld in T 386/04, where it was explained that supposedly contrary decisions had always been concerned with circumstances in which the amendment to the claim amounted to an abuse of the procedure.
According to T 386/04, an appellant (proprietor), whose patent has been revoked, is entitled to seek maintenance of the patent as granted even though its main request before the opposition division had only been the maintenance of the patent in more limited form. The exception to this is where to allow the proprietor to revert to the amended claims would amount to an abuse of procedure. According to the board, this long-standing principle is not contradicted by decisions T 528/93 or T 840/93 (OJ 1996, 335), which are concerned with new claims raising new issues, and is not contrary to the statement by the Enlarged Board of Appeal in decision G 9/91 (OJ 1993, 408), concerning the purpose of an appeal. In T 727/15 the board referring to T 386/04 admitted the main request into the proceedings (reversion to claims as granted after maintenance in more restricted form). In the case in hand such reversion did not constitute an abuse of procedure.
The board in T 28/10 extensively discussed T 123/85 (OJ 1989, 336) and the case law based on it (including T 386/04) holding that it did not follow from this case law that a patent proprietor must be able to revert to a broader version of the claims which it had not initially defended in the opposition proceedings, and thereby amend its case, without being subject to any procedural restrictions. In the case at issue, the patentee had sought to introduce into the appeal proceedings claims which had not been the basis of discussion before the opposition division. The board found that the legal situation had changed since T 123/85 and Art. 12(4) RPBA 2007 was now the relevant legal provision rather than case law based on that decision.
In T 2558/16, the board held that just because a patent proprietor had dropped its request for rejection of the opposition, or replaced it with other requests, in the first-instance proceedings did not mean that it could not go back on appeal to defending the version of the patent as granted. That being said, the patent proprietor was not entitled to do so unconditionally; it had to be requested and it was at the board's discretion to grant such a request. In exercising its discretion under Art. 12(4) RPBA 2007, the board had to consider the circumstances of the individual case before it (which, in the case in hand, meant especially the events in the opposition proceedings).