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.