Cal. Rev. & Tax. Code § 3951

The complaint shall include as defendants to the action, all persons who are known to plaintiff or who appear of record to have some interest in or claim or cloud on the land described in plaintiff’s complaint, arising prior to the date of the tax deed, other than persons owning a special assessment unless plaintiff seeks to determine the interest or claim of those persons. The state may be made a party defendant where the property was sold prior to September 10, 1984.