California Code, Penal Code - PEN § 18160

(1) A statement of the grounds supporting the issuance of the order.

(2) The date and time the order expires.

(3) The address of the superior court in which a responsive pleading should be filed.

(4) The date and time of the scheduled hearing.

(5) The following statement:

“To the restrained person:  This order is valid until the expiration date and time noted above.  You are required to surrender all firearms, ammunition, and magazines that you own or possess in accordance with Section 18120 of the Penal Code and you may not have in your custody or control, own, purchase, possess, or receive, or attempt to purchase or receive any firearm, ammunition, or magazine while this order is in effect.  A hearing will be held on the date and at the time noted above to determine if a more permanent gun violence restraining order should be issued.  Failure to appear at that hearing may result in a court making an order against you that is valid for a period of time between one to five years.  You may seek the advice of an attorney as to any matter connected with the order.  The attorney should be consulted promptly so that the attorney may assist you in any matter connected with the order.”

(b)(1) An ex parte gun violence restraining order shall be personally served on the restrained person by a law enforcement officer, or by a person as provided in Section 414.10 of the Code of Civil Procedure, if the restrained person can reasonably be located.

(2) When serving a gun violence restraining order, a law enforcement officer shall inform the restrained person of the hearing scheduled pursuant to Section 18165.

(3) When serving a gun violence restraining order, a law enforcement officer shall verbally ask the restrained person if the person has a firearm, ammunition, or magazine in the person's possession or under the person's custody or control.