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 of opposition (see H‑II, 3.1). If that is not the case a change of category should be refused.
Even if this condition is fulfilled, the Opposition Division should exercise 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.