For purposes of this title, a historic preservation (HP) modifying district may be applied only to properties within historic preservation district(s) (HPD) to permit special regulations where appropriate or necessary in addition to or in lieu of the development regulations otherwise set forth in the underlying zoning. (Also see the City’s HPP Section 5.0, Design Guidelines – Historic Preservation Modifying Districts.) (Ord. 3196 § 3, 2011).