73. Intervention by third parties. (1) A person other than the registered proprietor alleging an interest in a registered trademark in respect of which an application is made in Form TM 25, may apply to the registrar in Form TM 26 for leave to intervene, stating in the application the nature of the interest, and the registrar may refuse or grant the leave, after hearing (if so required) the parties concerned, upon such terms and conditions as the registrar may deem fit. (2) Before dealing in any way with the application for leave to intervene, the registrar may require the applicant to give an undertaking to pay such costs as in the circumstances the registrar may award to any party. 74. Application for correction of register under section 90(1) of the Act. (1) An application to the registrar under section 90 (1) of the Act for the alteration of the register by correction, change, cancellation, or striking out goods, or for the entry of a disclaimer or memorandum, may be made by the registered proprietor of the trademark or by such person as may satisfy the registrar that he or she is entitled to act in the name of the registered proprietor. (2) The application shall be made in Form TM 17, TM 19, TM 20, TM 21, TM 22, TM 23 or TM 32, as may be appropriate; but an application in Form TM 21, TM 22 or TM 32 shall be signed by the registered proprietor or other person entitled under this regulation unless in exceptional circumstances the registrar otherwise allows, or, in the case of Form TM 32 only, it is signed by an agent expressly authorised for the purpose of that application. (3) In the case of an application under sub regulations (1) and (2), the registrar may require such evidence by statutory declaration or otherwise as the registrar may think fit as to the circumstances in which the application is made. 2021