legal ground
Article 109 of the Detailed Rules for the Implementation of the Patent Law stipulates that for an international application for a patent right for utility model, the applicant may submit the revised specification, drawings and claims to the patent administration department of the State Council within 1 month from the date of going through the formalities for entering the national phase in China; For an international application for a patent for invention, the applicant for a patent for invention may take the initiative to propose amendments to the application for a patent for invention within three months from the date of notification at the substantive examination stage. The above amendments are called national amendments.