Decisions T 673/89 and T 685/90 prohibited the inclusion of equivalents. T 673/89 concerned a dual circuit braking system. The board held that the mere fact that the original claim did not indicate how the signals were transmitted in the brake circuits was not a basis for deliberately supplementing its teaching with a further embodiment not referred to in the application documents as originally filed. In T 685/90 the board stated that specific equivalents of explicitly disclosed features did not automatically belong to the content of a European patent application as filed, when this content was used as state of the art according to Art. 54(3) and (4) EPC 1973 against a more recent application. It therefore concluded that such equivalents could not belong to the content of a European patent application either, when this content was assessed to determine whether an amendment was admissible under Art. 123(2) EPC 1973. In T 265/88 the board refused to allow originally undisclosed equivalents to be added by using a wider technical term in place of the single technical means originally disclosed. T 118/88 had concluded that the obviousness of a feature was no replacement for the original disclosure.
In T 40/97 the board considered what the originally filed application taught the person skilled in the art and took the view that in a case where a number of generally similar embodiments were discussed in equivalent terms, the person skilled in the art would, in normal circumstances and when nothing pointed to the contrary, notionally associate the characteristics of an element of one embodiment described in some detail with the comparable element of another embodiment described in lesser detail.
In T 243/89 the applicant had originally claimed a catheter only for medical use; during examination proceedings he filed a further claim for its manufacture. The board of appeal saw no reason to refuse the filing of an additional method claim for forming the apparatus, in view of the similar wording and thus of the close interrelationship between both independent claims. Since the result of the activity was in itself patentable, such methods were also patentable unless the disclosure was insufficient.
In T 157/90 and T 397/89 it was stressed that it was insufficient for the generalisation of a feature to have only formal support in the application as filed. If, for example, the application as filed only described specific embodiments, and the feature's general applicability was not evident to the skilled person, then generalisation could not be allowed.