California Code, Penal Code - PEN § 18100

(a) A gun violence restraining order is an order, in writing, signed by the court, prohibiting and enjoining a named person from having in his or her custody or control, owning, purchasing, possessing, or receiving any firearms or ammunition.  This division establishes a civil restraining order process to accomplish that purpose.

(b) For purposes of this chapter, the term “ammunition” includes a “magazine” as defined in Section 16890.