California Code, Education Code - EDC § 90028

An indenture may include a clause relating to the bonds issued thereunder requiring the board to hold or cause to be held in trust the revenues or any part of revenues pledged to the payment of such bonds and the interest thereon, or to any reserve or other fund created by this article for the further protection of the bonds, and to apply such revenues or any part of revenues or cause them to be applied only as provided in the indenture.