For the purpose of advising whether an application to F1the appropriate tribunal should be made by or in respect of a patient who is liable to be detained or subject to guardianship F2. . . under Part II of this Act F3or a community patient, or of furnishing information as to the condition of a patient for the purposes of such an application, any registered medical practitioner F4or approved clinician authorised by or on behalf of the patient or other person who is entitled to make or has made the application—