The substantive examination of a divisional application should in principle be carried out as for any other application but the following special points need to be considered. The claims of a divisional application need not be limited to subject-matter already claimed in claims of the parent application. However, under Art. 76(1), the subject-matter may not extend beyond the content of the parent application as filed. If a divisional application as filed contains subject-matter additional to that contained in the parent application as filed and the applicant is unwilling to remedy this defect by removal of that additional subject-matter, the divisional application must be refused under Art. 97(1) due to non-compliance with Art. 76(1). It cannot be converted into an independent application taking its own filing date. Moreover, a further divisional application for this additional subject-matter should also be refused under Art. 97(1) due to non-compliance with Art. 76(1).

Amendments made to a divisional application subsequent to its filing must comply with the requirements of Art. 123(2), i.e. they may not extend the subject-matter beyond the content of the divisional application as filed (see T 873/94, OJ 10/1997, 456).

If the subject-matter of a divisional application is restricted to only a part of the subject-matter claimed in the parent application, this part of the subject-matter must be directly and unambiguously derivable from the parent application as being a separate part or entity, i.e. one which can even be used outside the context of the invention of the parent application (see T 545/92, not published in OJ).