California Code
ARTICLE 4 - Expense of Abatement
Section 5638.

5638. If the address of the encumbrancer is unknown to the commissioner, he shall state in the copy of the notice that the address is unknown to him and shall mail the copy addressed to the encumbracer at the county seat of the county in which the property is situated.

(Enacted by Stats. 1967, Ch. 15.)