Revenue and Taxation Code § 3957
CHAPTER 10. Rights of Purchaser of Tax-Deeded Property, or Any Other Person Claiming Through Him, to Bring Action to Determine Adverse Claims to or Clouds Upon Tax-Deeded Property Purchased From the State
Any summons that is issued shall contain the matters required by Section 412.20 of the Code of Civil Procedure, and in addition, a description of the property and a statement of the object of the action. In the summons, the unknown defendants shall be designated as they are in the complaint.