An amendment can be in the form of a change in the category of a claim, possibly combined with a change in the technical features of the invention. Firstly it must be clear that this amendment is necessitated by grounds for opposition (see H‑II, 3.1). If that is not the case, a change of category should be is refused.
Even if this condition is fulfilled, the opposition division should exercise exercises great caution in allowing a change of claim category, since the protection as conferred by the claims may thus be extended (Art. 123(3)). Examples are given in the following sections. Note that these examples could also give rise to issues under Art. 123(2).