California Code, Financial Code - FIN § 506

Whenever he or she deems it expedient, the commissioner may call a meeting of the stockholders of any bank or trust company.  Notice of the time and place of the meeting shall be given to each stockholder by a notice mailed to the stockholder by registered mail at the stockholder's last known address at least 15 days before the date of the meeting.  Any expenses of such meeting shall be borne by the bank or trust company.