California Code, Code of Civil Procedure - CCP § 1282.6

(a) A subpoena requiring the attendance of witnesses, and a subpoena duces tecum for the production of books, records, documents, and other evidence, at an arbitration proceeding or a deposition under Sections 1283and 1283.05 for the purposes of discovery, shall be issued as provided in this section. In addition, the neutral arbitrator upon their own determination may issue subpoenas for the attendance of witnesses and subpoenas duces tecum for the production of books, records, documents, and other evidence.

(b) Subpoenas shall be issued, as of course, signed but otherwise in blank, to the party requesting them, by a neutral association, organization, governmental agency, or office if the arbitration agreement provides for administration of the arbitration proceedings by, or under the rules of, a neutral association, organization, governmental agency or office, or by the neutral arbitrator.

(c) The party serving the subpoena shall fill it in before service. Subpoenas shall be served and enforced in accordance with Chapter 2 (commencing with Section 1985) of Title 3 of Part 4 of this code.