Where a trademark is registered by deception, the registered trademark may be declared invalid. If a registered trademark is not used for three consecutive years without justifiable reasons, any unit or individual may apply for cancellation of the registered trademark. When using a registered trademark, you can indicate "registered trademark" or a registration mark, which is the right, not the obligation, of the trademark registrant. If a trademark registrant fails to apply for renewal of registration after the expiration of the extension period, its registered trademark will be cancelled.