Special Permits allow a use that would not be appropriate generally or without restriction throughout the zone, but which if controlled as to number, area, location or relation to the neighborhood, would promote the public health, safety, morals, or general welfare. Such uses may be permitted in such zone by special permit, by specific provision for such special permit uses made in the Zoning By-Laws. Special permits shall be issued only for uses which are in harmony with the general purpose and intent of the Zoning By-Laws and only upon subjecting the specially allowed use to general or specific provisions set forth in the Zoning By-Laws, as appropriate. Special permits may impose conditions, safeguards and limitations on time and/or use. Every special permit must be duly recorded before it expires in order to take effect.