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 49/11 the board found that it is well-established that subject-matter is not added by a change of claim category per se. The relevant question to be answered was whether there was a basis for the new claim category. In the case in issue the originally filed product claims were changed to claims to a method of treatment. The board, after analysing the disclosure of the application as filed, concluded that this change of category complied with Art. 123(2) EPC.