Cal. Rev. & Tax. Code § 2206.5

“Costs mandated by the voters” means any increased costs expressly mandated upon a local agency or school district after September 2, 1975, by any statute or any amendment to the State Constitution adopted or enacted pursuant to the approval of a statewide ballot measure by the voters. “Costs mandated by the voters” does not include costs which are specifically reimbursed or funded by the terms of such ballot measure.