Ancillary Activities. The use permit may authorize limited ancillary activities such as weddings, receptions, fund raisers or similar events attended by nonguests, subject to conditions which are necessary to satisfy Section 17.20.030C, including, but not limited to, restrictions upon the frequency and time of holding events, duration thereof, and the maximum number of persons attending. Unless expressly authorized in the use permit, such ancillary activities are prohibited.