California Code, Public Utilities Code - PUC § 829

(b)(1) Except for Section 828, a telephone corporation that is not regulated under a rate-of-return regulatory structure is exempt from this article.  This subdivision does not exempt a telephone corporation that is also an electrical corporation or a gas corporation, unless the commission determines the telephone corporation is exempt pursuant to subdivision (c).  As used in this subdivision, a “rate-of-return regulatory structure” means a system under which the rates and charges of the telephone corporation are limited by a maximum permissible price that may be charged for a specific service.  Telephone corporations regulated by a framework under which they may exercise pricing flexibility for all or most of the services offered are not regulated under a rate-of-return regulatory structure.

(2) Notwithstanding paragraph (1), the commission may impose any requirement of this article on a telephone corporation if the commission finds, in a proceeding in which the telephone corporation is or may become a party, that the application of any provision of this article is required by the public interest.