(1) This section applies to an appointment of—
(a) a property agent, other than an appointment for an open listing or a sole or exclusive agency; or
(b) a resident letting agent.
(2) The appointment must state, in writing, that the appointment may be revoked by either party giving the other party at least 30 days written notice of the revocation, unless the parties agree, in writing, to an earlier day for the appointment to end.