California Code, Penal Code - PEN § 850

(a) A telegraphic copy of a warrant or an abstract of a warrant may be sent by telegraph, teletype, or any other electronic devices, to one or more peace officers, and such copy or abstract is as effectual in the hands of any officer, and he shall proceed in the same manner under it, as though he held the original warrant issued by a magistrate or the issuing authority or agency.

(b) Except as otherwise provided in Section 1549.2 relating to Governor's warrants of extradition, an abstract of the warrant as herein referred to shall contain the following information:  the warrant number, the charge, the court or agency of issuance, the subject's name, address and description, the bail, the name of the issuing magistrate or authority, and if the offense charged is a misdemeanor, whether the warrant has been certified for night service.

(c) When the subject of a written or telegraphic warrant or abstract of warrant is in custody on another charge, the custodial officer shall, immediately upon receipt of information as to the existence of any such warrant or abstract, obtain and deliver a written copy of the warrant or abstract to the subject and shall inform him of his rights under Section 1381, where applicable, to request a speedy trial and under Section 858.7 relating to Vehicle Code violations.