“Qualified historical property” for purposes of this article, means privately owned property which is not exempt from property taxation and which meets either of the following:
(a)
Listed in the National Register of Historic Places or located in a registered historic district, as defined in Section 1.191-2(b) of Title 26 of the Code of Federal Regulations.(b)
Listed in any state, city, county, or city and county official register of historical or architecturally significant sites, places, or landmarks.
Source:
Section 50280.1, https://leginfo.legislature.ca.gov/faces/codes_displaySection.xhtml?lawCode=GOV§ionNum=50280.1..