Cal. Gov. Code § 16743

If the right to do so has been reserved in the resolution adopted in conformity with Section 16731, 16731.5, or 16731.6, temporary or interim bonds, notes, certificates, or receipts may be issued and delivered in lieu of definitive bonds or notes, and shall be exchangeable for definitive bonds or notes when they are executed and available for delivery. The temporary securities shall conform to the resolution, and the signature of the Treasurer alone, which may be by signature stamp, shall be sufficient execution thereof.