A principal may avoid repetitious listings by providing HUD with a complete master list, acceptable to the Participation Control Officer, of all projects in which the principal has participated. Where such a list has been provided, the principal may submit a certificate which refers to the master list and which supplements it by the addition of all information required under Sec. 200.219 with respect to occurrences since the date of the master list (including subsequent occurrences with respect to the projects on the master list as well as subsequent projects). Partners, corporate officers, directors and stockholders may likewise refer to and thereby incorporate their firm's master list when they certify.