Cal. Const. art. XIII, § 6
California Constitution Article XIII, Section 6
The failure in any year to claim, in a manner required by the laws in effect at the time the claim is required to be made, an exemption or classification which reduces a property tax shall be deemed a waiver of the exemption or classification for that year. (Sec. 6 added Nov. 5, 1974, by Prop. 8. Res.Ch. 70, 1974.)