California Code, Government Code - GOV § 53758

(a) “Specific benefit” means a benefit that is provided directly to a payor and is not provided to those not charged.  A specific benefit is not excluded from classification as a “specific benefit” merely because an indirect benefit to a nonpayor occurs incidentally and without cost to the payor as a consequence of providing the specific benefit to the payor.

(b) “Specific government service” means a service that is provided by a local government directly to the payor and is not provided to those not charged.  A specific government service is not excluded from classification as a “specific government service” merely because an indirect benefit to a nonpayor occurs incidentally and without cost to the payor as a consequence of providing the specific government service to the payor.  A “specific government service” may include, but is not limited to, maintenance, landscaping, marketing, events, and promotions.

(c) The local government bears the burden of proving by a preponderance of the evidence that a levy, charge, or other exaction imposed for a specific benefit or specific government service is not a tax, that the amount is no more than necessary to cover the reasonable costs to the local government in providing the specific benefit or specific government service, and that the manner in which those costs are allocated to a payor bear a fair or reasonable relationship to the specific benefits or specific government services received by the payor.