Cal. Code of Civil Procedure § 751.09

At the time of filing the complaint the plaintiff shall file with it his affidavit fully and explicitly setting forth and showing: (a) The character of the plaintiff’s estate, right, title, interest, or claim in, and possession of, the property, the period it has existed, and from whom obtained. (b) Whether or not the plaintiff has ever made any conveyance of all or any part of the property, or any interest therein, and if so when and to whom, and a statement of any and all subsisting mortgages, deeds of trust, and other liens thereon. (c) That the plaintiff does not know and has never been informed of any other person who claims or who may claim any interest in or lien upon all or any part of the property adversely to the plaintiff, or if the plaintiff does know or has been informed of any such person, the name and address of such person. If the plaintiff is unable to state any of the required matters, the plaintiff shall set forth and show fully and explicitly the reasons for such inability. Such affidavit shall constitute a part of the judgment-roll. If the plaintiff is a corporation, the affidavit shall be made by an officer thereof. If the plaintiff is a person under guardianship or conservatorship, the affidavit shall be made by the guardian or conservator.