Rev. & Tax. Code, § 20804

(a) “Owner of a residential dwelling” includes all of the following:

(1) An individual with an ownership interest of a vendee, who is in possession of the residential dwelling under a land sale contract, provided that the contract or memorandum thereof is recorded, and only from the date of recordation of the contract or memorandum thereof in the office of the county recorder of a participating county in which the residential dwelling is located.

(2) An individual with an ownership interest of a holder of a life estate in the residential dwelling, provided that the instrument creating the life estate is recorded, and only from the date of recordation of that instrument in the office of the county recorder of a participating county in which the residential dwelling is located.

(3) If the residential dwelling is located within a participating county, an individual with a joint-tenant or tenant-in-common ownership interest in the residential dwelling, or the interest of a tenant where title is held in tenancy by the entirety or as community property.

(4) An individual with an ownership interest in the residential dwelling and the title to the residential dwelling, located within a participating county, is held in trust.

(5) For purposes of this chapter, an individual who is the registered owner of a mobilehome attached to a permanent foundation and assessed as real property.

(b) An ownership interest described in subdivision (a) shall be required to be evidenced by a duly recorded instrument in the office of the county recorder of a participating county in which the residential dwelling is located.