Except as otherwise expressly provided by law, the seal of a court need not be affixed to any proceeding therein, or to any document, except to the following:
(a) A writ.
(b) A summons.
(c) A warrant of arrest.
Section 153
Code Civ. Proc. § 153 — under California Code Civ. Proc..
Code Civ. Proc. § 153