Cal. PUC § 742.1

(a) The commission shall, by rule or order, adopt and enforce operating requirements for every corporation or person, other than a telephone corporation, which, as part of the services furnished, furnishes operator-assisted services by other than a telephone corporation having tariff schedules on file with the commission. These requirements shall include, but not be limited to, a requirement that furnishing these operator-assisted services for telephone calls within a service area is prohibited unless the commission, after instituting a proceeding for the purpose, finds and determines that to permit these operator-assisted services is in the public interest.

(b) The commission shall require every telephone corporation which publishes a directory of subscribers to include in that directory information comprising the substance of this section and the rules and orders of the commission adopted pursuant to this section.