Limited exceptions to the rule against reformatio in peius exist. In G 1/99 (OJ 2001, 381) the Enlarged Board of Appeal answered the question referred to it in T 315/97 date: 1998-12-17 (OJ 1999, 554), namely, "Must an amended claim which would put the opponent and sole appellant in a worse situation than if he had not appealed – e.g. by deleting a limiting feature of the claim – be rejected?".
The Enlarged Board held that in principle such a claim must be rejected. However, an exception to this principle might be made where the opposition division had allowed an inadmissible amendment. In the case at issue the opposition division had done just that with the agreement of the proprietor, who was thus not adversely affected by the decision and unable to appeal. The patent proprietor (respondent) had filed during the appeal proceedings a main request including the added (and unallowable) limiting feature, and an auxiliary request deleting it (and thus widening the claim). The Enlarged Board found that the main request had to be rejected because it did not meet the requirements of the EPC. Moreover, if the principle of reformatio in peius were to be applied without considering the specific circumstances of the case, the auxiliary request would also have to be rejected because it would put the opponent (appellant) in a worse situation than if it had not appealed. The only possible course the board could then take would be to revoke the patent, there being no further remedy for the proprietor. The proprietor would thus definitively lose any protection as a direct consequence of an inadmissible amendment being held allowable by the opposition division. The Enlarged Board considered it inequitable for the patent proprietor not to be given a fair opportunity to mitigate the consequences of errors of judgment made by the opposition division. The patent proprietor should thus be allowed to file requests in order to overcome this deficiency, as follows:
- in the first place, for an amendment introducing one or more originally disclosed features which limited the scope of the patent as amended;
- if such a limitation was not possible, for an amendment introducing one or more originally disclosed features which extended the scope of the patent as maintained, but within the limits of Art. 123(3) EPC 1973;
- finally, if such amendments were not possible, for deletion of the inadmissible amendment, but within the limits of Art. 123(3) EPC 1973, even if, as a result, the situation of the opponent was made worse.