4.2.3 Obvious correction – immediately evident that nothing else would have been intended than what is offered as the correction
In J 5/06 the Legal Board, referring to T 158/89 (which had not accepted correction in case of two equally plausible alternatives for a percentage range of a component), held that establishing that a suggested set of documents was a probable and suitable replacement did not amount to establishing that nothing else would have been intended. This latter threshold implied that there was only one single plausible replacement – the one which the skilled person would have deduced from those parts of the application which made up the disclosure of the invention. For the case in hand the Legal Board concluded that, to the contrary, a complete exchange of the application documents would quite obviously open the door to a plethora of plausible replacements. See also J 16/13, also relating to replacement of application documents; T 15/09 and T 846/16, both relating to correction of a feature in the claims at issue.
In T 955/92 the reasons given by the appellant to show that only the requested correction could have been intended were not based on the level of general knowledge on the date of filing. In order to arrive at the conclusion that the requested correction was the only physically meaningful one, experiments had had to be performed which needed more than common general knowledge, and the results thereof would not have been available on the date of filing. The request for correction was therefore refused.
In T 438/99 the board held that the fact that a term or phrase could not be interpreted or construed because it was unresolvably ambiguous did not necessarily mean that its deletion was a permissible amendment under Art. 123(2) EPC 1973. There remained a residual clear meaning in the ambiguous term, e.g., as in this case, that a specific direction was taught, and suppressing that fact resulted in a different technical teaching. Therefore, the second condition of R. 88 EPC 1973 (immediately evident that nothing else would have been intended than what is offered as the correction) was not met by the offered correction of deleting the feature without replacement.
T 1728/07 concerns the correction of an error in a structural formula representing oxazoline derivatives. The board recalled that according to R. 139, second sentence, EPC it must be immediately apparent to the skilled person that (i) an error has occurred and (ii) how it should be corrected. With respect to requirement (ii), it must be decided whether the corrected feature is directly and unambiguously derivable from the content of the application as originally filed taken as a whole. This requirement was found by the board to be fulfilled.
In T 1508/08, the board concluded that the second condition for allowability of a correction under R. 139 EPC was not met. In its view, not only did the correction fail to solve the existing problems of a lack of clarity, but it actually made things even less clear. That was one reason why the skilled person would not have contemplated the correction made by the appellant proprietor. Even if it were assumed in the appellant's favour that the skilled person would have contemplated this correction, it was not the only one possible, but rather one of at least three conceivable corrections.
In T 455/09 the board held that in the case at issue the skilled person could not exclude one of two options with certainty, so that it was not directly and unambiguously evident that nothing else could have been intended other than the proposed correction. For another case where other corrections were equally possible, see T 923/13.
In T 141/14 the board held that the amendment of the feature "vanadium" to "vanadium oxide" did not meet the requirements of R. 139 EPC because the proposed correction was only one of several options which would occur to the skilled person. As long as there was at least one further possibility of correction, the criterion within R. 139 EPC that "the correction must be obvious in the sense that nothing else would have been intended than what is offered as the correction" was not fulfilled.
In T 244/19 the appellant (patent proprietor) had argued that it was obviously an error that original claim 6 referred back to just one of the two independent product claims. The board, however, did not consider it immediately evident that nothing other than a reference to both could have been intended.