(1)  Subject to rule 295 , the name of a person is not to be used in any proceeding as litigation guardian of any party under disability unless –

(a) the person has signed a written authority for that purpose; and

(b) that authority has been filed in the registry.

(2)  A practitioner who files a notice of appearance for a person under disability is to make and file an affidavit at the same time.

(3)  The affidavit is to be in accordance with the prescribed form.