The trust mechanism is today the common method of issuing corporate bonds. If the bonds are mortgage bonds, the corporation pursuant to a trust agreement, executes or assigns the mortgage to a trustee, usually a bank or trust company which holds the mortgage for the benefit of all the bondholders. In other situations collateral security is placed in the hands of the trustee. In both cases, the trustee certifies the corporation's bonds as having been issued under the terms of the trust indenture.