In all cases in which amendments are requested by a patentee which were compatible with Art. 123 EPC, Art. 102(3) EPC 1973 (now Art. 101(3)(a) and R. 82 EPC) conferred on the opposition division and the board of appeal jurisdiction, and thus the power, to decide on the amended patent in the light of the requirements of the EPC as a whole (T 472/88). This jurisdiction was thus wider than that conferred by Art. 102(1) and (2) EPC 1973 (both now Art. 101(2) EPC) which expressly limited jurisdiction to the grounds of opposition mentioned in Art. 100 EPC. When substantive amendments were made to a patent, both instances have the power to deal with grounds and issues arising from those amendments even if they were not (and could not be) specifically raised by an opponent pursuant to R. 55(c) EPC 1973 (now R. 76(2)(c) EPC) (T 227/88, OJ 1990, 292; see G 9/91, OJ 1993, 408; T 472/88 and T 922/94).
The question whether and, if so, to what extent an opposition division or a board of appeal has the power to examine the clarity of amended claims derived from combinations of claims as granted was addressed in T 1459/05. The board decided not to follow the existing case law, according to which there is no power to examine under Art. 84 EPC where the amendments creating the lack of clarity consist of a combination of claims as granted which is in line with the correct cross-references. The board found that an exception had to be made in the case before it because the assessment of the claimed subject-matter depended on the technical significance of the sole added feature, since any difference from the prior art could only be defined on the basis of that feature. However, its technical significance was so unclear for the skilled person that any such difference was not apparent or at least could not be identified with a degree of uncertainty still reasonably acceptable to the skilled person. Irrespective of the circumstances of the specific case and in view of the sharp increase in the number of patent claims over the preceding years, the board also questioned the extent to which the clarity of all possible combinations claimed in a complex set of claims was - or even could be - examined so thoroughly before grant that it could be assumed that all clarity problems had been resolved, with the result that further examination in opposition proceedings could ultimately be dispensed with. The board held that it had to be able to exercise its discretion and deviate, exceptionally on a case-by-case basis, from the general practice ruling out any power of examination under Art. 84 EPC in the case of combinations of claims as granted. In particular, discretion had to be exercised where a strict application of the prescribed approach, which in principle excluded the raising of an objection on the grounds of clarity, would give rise to a situation in which a further examination of the patent documentation, e.g. in relation to novelty and inventive step, would be made considerably more difficult or might not even lead to a meaningful result (cf. T 589/09).
In T 656/07 the lack of clarity arose - at least in part - from the amendments that had been carried out after grant of the patent. The board held that this lack of clarity could be objected to in opposition proceedings because it was generated by the amendments made during this procedure, even if the contested feature as such was already present in the claims as granted but in another combination. It was not enough to state that a feature was present in the granted version in order to limit the power of investigation of the board as far as clarity objections arising from an amendment was concerned. It was also necessary to ascertain the effect produced by the amendments introduced into the claim as a whole since a feature of a claim was not to be seen in isolation, but through its interaction with the other features of the claimed combination. In the opinion of the board it could not be stated that there was a general rule in the jurisprudence that a combination of granted claims should not be challenged for lack of clarity. Whenever amendments were requested by a patentee in the course of opposition proceedings, Art. 101(3)(a) EPC conferred upon both the opposition division and the boards of appeal jurisdiction and thus the power to apply the whole of the EPC including Art. 84 EPC.
In T 648/96 the board found that the opposition division's failure, in the contested decision, to address the substance of the opponent's "lack of clarity" objections to the amended documents was a substantial procedural violation; under Art. 102(3) EPC 1973 (now Art. 101(3)(a) and R. 82 EPC), it should have examined of its own motion whether the amendments complied with Art. 84 EPC and Art. 123(2) and (3) EPC 1973 (see also T 740/94).
In T 503/96 the board considered the criteria for the need for an additional search in relation to restrictive amendments. It referred to the Guidelines B-III, 3.5, which state, "In principle, and in so far as possible and reasonable, the search should cover the entire subjectmatter to which the claims are directed or to which they might reasonably be expected to be directed after they have been amended...”. The board stated that whether or not to commission an additional search in a particular case was a matter for the administrative discretion of the opposition division, but if an inappropriate criterion was invoked when exercising this discretion, doubt would inevitably be raised as to whether the discretion was reasonably exercised.
Since, in the case of amendment of the claims in the course of opposition or appeal proceedings, such amendments are to be fully examined as to their compatibility with the requirements of the EPC (G 9/91, OJ 1993, 408, point 19 of the Reasons), it was not inappropriate for an opponent to make observations on a possible need for an additional search to enable this full examination to be carried out (Guidelines D-VI, 5). The judgment on whether an additional search was necessary and the obligation to perform this search if it was judged to be necessary were administrative matters for the EPO.