Cal. Code Regs. tit. 2, § 1898.3 – Eligible Collateral.

(a) The loan to appraised value ratio is not in excess of 80 percent, unless such loan is federally insured or guaranteed;
(b) The loan has been outstanding at least six months prior to acceptance;
(c) No payment on the loan is more than thirty days past due prior to acceptance.

All promissory notes pledged to secure state deposits may be approved by the Treasurer. The Treasurer may accept as eligible, promissory notes secured by first mortgages and first trust deeds upon residential real property located in California, provided that: