Principle of oneness: also known as "one invention and one application principle". It means that the application for a patent for invention or utility model should be limited to the invention or utility model, and the application for a patent for design should be limited to the design used by the product.
Principle of first application: If two or more applicants apply for a patent for the same invention-creation, the patent right shall be granted to the first applicant.
Principle of priority: If a patent applicant files a patent application for an invention-creation with the same theme within the statutory time limit after filing the patent application for the first time, the date of the first application shall be the filing date. This right is called priority, and the legal time limit here is the priority time limit.
Principle of Formal Legality: All procedures of patent application must be handled in written form or other forms stipulated by China National Intellectual Property Administration Patent Office, otherwise it will be invalid.