In addition to the districts listed above, the following zoning may be invoked upon specific parcels of land as provided in this ordinance:
"PUD-R" PLANNED RESIDENTIAL DEVELOPMENT DISTRICT: A district providing for flexibility of design standards for multi-family residential use. Extensive development plans are required.
"PUD-C" PLANNED COMMERCIAL DISTRICT: This district is to provide for and encourage the grouping of business buildings into "centers" in keeping with the modern concepts of office, service and shopping center design.
"COMMUNITY UNIT PLAN" This Plan provides for flexibility of design standards for mixed-use development allowing for residential and accessory uses such as churches, schools and daycare facilities.