Cal. Fin. Code § 1484
With the approval of the commissioner a commercial bank may accept drafts or bills of exchange drawn upon it having not more than three months' sight to run, exclusive of days of grace, drawn by banks or bankers in foreign countries for the purpose of furnishing dollar exchange as required by the usages of trade in the respective countries; provided, no commercial bank shall accept such drafts or bills of exchange for any one bank to any amount exceeding 10 percent of the sum of the shareholders' equity, allowance for loan losses, capital notes, and debentures of the accepting bank unless the draft or bill of exchange is accompanied by documents conveying or securing title or unless the bank is secured by some other adequate security. A commercial bank shall not accept such drafts or bills, whether secured or unsecured, in the aggregate to an amount exceeding 50 percent of the sum of its shareholders' equity, allowance for loan losses, capital notes, and debentures.
Ca. Fin. Code § 1484