Cal. Gov. Code § 29832

Whenever the county auditor draws a warrant upon the treasury in an amount in excess of the balance of the fund, the county auditor shall present it to the treasurer for registration. The treasurer shall endorse upon its back the date of presentation by the county auditor, that it is not paid for lack of funds, and that it bears interest at the rate fixed pursuant to law from the date of the registration to and including the date of maturity or the date upon which the treasurer first advertises that is redeemable upon presentation if it bears no date of maturity. Warrants so endorsed by the treasurer are registered warrants.