5.2.1 Scope of examination not limited to grounds raised pursuant to R. 76(2)(c) EPC

Amendments of the claims or other parts of a patent in the course of opposition proceedings are to be examined as to their compatibility with the requirements of the EPC (Art. 101(3) EPC). When amendments are made to a patent, opposition divisions (as well as the boards of appeal) have the power to deal with grounds and issues arising from those amendments even if they were not specifically raised by an opponent pursuant to R. 76(2)(c) EPC (T 227/88, OJ 1990, 292; G 9/91, OJ 1993, 408, G 10/91, OJ 1993, 420, point 19 of the Reasons, respectively; T 472/88; T 922/94; T 1437/15; see also T 459/09; see also chapter IV.C.5.2.2 below; for the extent of the power to examine amended claims for compliance with Art. 84 EPC, see G 3/14, OJ 2015, A102, and chapter IV.C.5.2.2 below).

Where amended claims were introduced in the opposition proceedings there could be no objection to the opponent's submitting new citations and new arguments against the new claims that challenged inventive step for the first time (T 623/93). The examination by the opposition division of a new submission justified in this way was in keeping with G 9/91 (OJ 1993, 408, point 19 of the Reasons).

In T 1437/15 the board pointed out that the grounds for opposition specified in Art. 100 EPC concerned only the maintenance of a granted patent (Art. 101(1) and (2) EPC). By contrast, where a patent was amended during opposition proceedings, it could be maintained as so amended only if, taking into consideration the amendments made, it met the requirements of the EPC (Art. 101(3) EPC).

In T 693/98 the board dealt with the question as to whether, on the proper interpretation of Art. 102(3) EPC 1973 (Art. 101(3)(a) EPC), the fact that an amendment to the claims has been made in opposition proceedings opens the possibility for an opponent to raise an objection under Art. 123(2) EPC to all the amendments to the claims including those made before the patent was granted, even if such objection was not originally raised and substantiated as a ground for opposition. Citing G 10/91 (OJ 1993, 420, point 19 of the Reasons) the board concluded that only the amendments made during opposition or appeal proceedings, not those made before grant, must be examined for compliance with the requirements of the EPC (see also T 301/87, OJ 1990, 335). Cited in T 2696/16.

The introduction of a feature into an independent claim, which feature was present in the claims and in the description as granted, could not be considered as an amendment which legitimated the admittance of Art. 100(b) EPC as a fresh ground of opposition, which required that a European patent as a whole had to disclose the invention in a manner sufficiently clear and complete for it to be carried out by a person skilled in the art (T 1053/05; cf. also T 739/08 and T 565/13).

In T 2155/17 the board considered that the new added-matter objection in question related to the amendment and not to the combination of features in the claims as granted, and therefore did not constitute a fresh ground in the sense of G 10/91 (OJ 1993, 420).

In T 895/18 the board cited G 9/91 (OJ 1993, 408, point 19 of the Reasons) and concluded that the EPC required that, in the case of amendments in opposition or appeal proceedings, a full examination had to be undertaken of the amendments and therefore in particular of the claims resulting from the amendments. The board rejected a "parallelism" between the treatment of unclear features and of added matter, as suggested by the appellant (proprietor), as this disregarded the fact that, in contrast to added matter, lack of clarity was not one of the grounds for opposition according to Art. 100 EPC.

In T 571/19, the board observed that Art. 101(3)(a) EPC required that new claim requests be examined for compliance with the EPC requirements. This did not extend to clarity where granted claims had been combined (G 3/14 – see also chapter IV.C.5.2.2) or to the requirement of unity of invention (G 1/91, headnote), but compliance with Art. 123(3) EPC always had to be established (see G 9/91 and G 10/91, point 19 of the Reasons; T 648/96; T 1302/06). However, it was not apparent from the opposition division's decision why it had found the claims of the auxiliary request on which the decision was based to be in keeping with Art. 123(3) EPC, and so the decision was insufficiently reasoned for the purposes of R. 111(2) EPC. The board considered it irrelevant that Art. 100(c) EPC had not been cited as a ground for opposition and that the opponent had not raised any objection under Art. 123(2) EPC; the amended claims should nevertheless have been examined for compliance with Art. 123(3) EPC.