Before the Patent Reexamination Board makes an examination decision, the patentee may delete the claim or the technical scheme contained in the claim. The patentee can only modify the claim through merger within the defense period of the following three situations:
1. Invalid declaration request;
2, for the claimant to increase the reasons for invalidation or supplementary evidence;
3. Reasons or evidence for invalidation put forward by the Patent Reexamination Board.