Every tax on improvements assessed to a person other than the assessee of the land on which they are located may become a lien on the real property of the owner of such improvements or be assessed on the unsecured roll. In order for such tax on improvements to be a lien on any parcel of real property of the owner of such improvements, the fact of such lien must be indicated on the secured roll where any such parcel of real property is listed.
Source:
Section 2188.1, https://leginfo.legislature.ca.gov/faces/codes_displaySection.xhtml?lawCode=RTC§ionNum=2188.1..