In T 172/82 (OJ 1983, 493) the deletion of a feature in a claim was considered admissible because the sole purpose of such deletion was to clarify and/or resolve an inconsistency. And in T 271/84 (OJ 1987, 405) it was stated that an amendment to a claim to clarify an inconsistency did not contravene Art. 123(2) or Art. 123(3) EPC 1973 if the amended claim had the same meaning as the unamended claim, on its true construction in the context of the specification.
In T 758/92 the board allowed the deletion of a feature because it was clearly inconsistent with the teaching disclosed in the application as filed, and there was a clear basis in the original disclosure for its deletion. A skilled reader of the original application documents would have realised that the feature to be deleted was erroneously introduced in the claim because the resulting definition was contradictory to the functioning of the described embodiment of the invention.
In case T 60/90 the applicant had deleted the lower limit of a temperature range in order to eliminate an inconsistency between the claims and the examples. Resolving this inconsistency was found unobjectionable under Art. 123(2) EPC 1973. The board held that, (1) the feature in question was not explained as essential in the disclosure (it was originally a preferred embodiment), (2) it was not, as such, essential for the function of the invention (the examples used a lower temperature - the source of the contradiction), and (3) its removal required no real modification of other features to compensate for the change.
In T 609/95 the board took the position that where a drafting defect or inconsistency in an application would be evident to a reader skilled in the art, the person to whom the application is addressed, it is reasonable to suppose that he would, in the light of the content of the application, attempt to formulate a notional amendment which would enable him to make sense of what he reads, and to the extent that the amendment might be said to leap to the mind of the reader, although perhaps only after close study of the document, it can be regarded as implicit in the application and would not contravene Art. 123(2) EPC 1973, if effected in practice (see also T 887/97 for such amendment during opposition appeal proceedings).
In T 749/03 the respondent (patent proprietor) had made reference to T 190/99, which discussed the possibility of amending a granted claim to replace an inaccurate technical statement, which was evidently inconsistent with the totality of the disclosure of the patent, with an accurate statement of the technical features. According to that decision, the skilled person, when considering a claim, should rule out interpretations which were illogical or did not make technical sense. It appeared that in the present case T 749/03 a similar situation arose - claim 5 as originally filed would, if taken alone, not make technical sense, and even the simple addition of its features to the features of claim 1 would result in an inadequately defined apparatus. However, by taking into account the whole disclosure of the patent the skilled person might arrive at a technically sensible interpretation of the claim.
In that context reference was also made to T 371/88 (OJ 1992, 157), which concerned the admissibility of amending a granted claim to replace a restrictive term with a less restrictive term. The board in that case had ruled that such replacement was permissible under Art. 123(3) EPC 1973 if examination of the extent of protection conferred by the granted claim resulted in the following conclusions: (a) the restrictive term in the granted claim was not so clear in its technical meaning in the given context that it could be used to determine the extent of protection without interpretation by reference to the description and the drawings of the patent; (b) it was quite clear from the description and the drawings of the patent and also from the examination procedure up to grant that the further embodiment belonged to the invention and that it had never been intended to exclude it from the protection conferred by the patent. In the present case (T 749/03), having regard to claim 1 alone, the features relating to the second (transmission) grating were perfectly clear in their technical meaning. However, in combination with claim 5 they would only make sense if reference were made to the description and drawings. Therefore requirement (a) was met. Further, there could be no doubt that the applicant had not waived that embodiment. Hence requirement (b) was also met.
In T 1464/05, assessing whether the amendment added subject matter under Art. 123(2) EPC, the Board said that the further attempt of the respondent/patent proprietor to see in the latter upper ends of range values a removable inconsistency in the application as filed could not, in the context of a wholly consistent and clear disclosure of the application, be accepted.