2. Article 66 of the Detailed Rules for the Implementation of Patents in People's Republic of China (PRC) stipulates: "After the expiration of the patent right for inventions and utility models, the patentee or obligee may apply for invalidation of the patent."
3. Article 68 of the Detailed Rules for the Implementation of Patents in People's Republic of China (PRC) stipulates: "The patentee or obligee may file an application for invalidation of a patent in China National Intellectual Property Administration, and the obligee who files the application shall provide proof of his rights."