Historical significance is determined using codified designation criteria. Federal designation criteria for listing in the National Register were established as part of the National Historic Preservation Act and implementing regulations. California Register criteria were adopted and codified as Sec. 5024 of the California Public Resources Code. Local designation criteria are established through local ordinance. All levels tier off federal standards and include criteria associated with: significant historic events or patterns of events; important people, social and cultural groups; worthy architecture; innovative engineering, technology, use of materials and quality workmanship.