How to modify the international patent application?

Modify the background part to adapt it to the claimed subject matter. The independent claim is written in accordance with Article 22 of the Detailed Rules for the Implementation of the Patent Law, and the background technology part of the specification shall record the contents related to the existing technology mentioned in the preface of the independent claim, and quote the documents reflecting these background technologies. If the examiner finds that the comparison file is closer to the subject to be protected than the existing technology cited by the applicant in the original specification through retrieval, the applicant shall be allowed to modify the specification, add the contents of the file to this part, quote the file, and delete the contents describing the irrelevant existing technology at the same time. It should be pointed out that this modification actually adds something that is not recorded in the claims and specifications of the original application, but it is allowed according to international practice because the modification only involves the background technology and not the invention itself, and the added content is the known prior art before the filing date.