Proactive modification and correction of application documents is also a procedure that applicants can choose according to their needs. Utility model and design patent applications are only allowed to submit active amendments within 2 months from the filing date; invention patent applications are only allowed to be submitted on the date of filing a request for substantive examination and receiving a notice from the Patent Office that the invention patent application has entered the substantive examination stage. Actively modify the application documents within 3 months.