(1) Application for trademark opposition; (2) Clear request and factual basis, together with relevant evidence materials; (3) Copy of the preliminary approval announcement of the opposed trademark; (4) Opponent’s Proof of identity. (5) If you entrust a trademark agency to handle trademark opposition applications, you must also submit a trademark agency power of attorney. Article 44 stipulates that if a registered trademark violates the following provisions, the Trademark Office shall declare the registered trademark invalid; other units or individuals may request the Trademark Review and Adjudication Board to declare the registered trademark invalid.