Notice of demand must be in Form No. 28 for demands under section 156 following an order under section 210. Notice of demand issued pursuant to an order under the statutory provision for tax demands in advance tax proceedings must be served in Form No. 28 notwithstanding any contrary provision in rule 15; this requirement appears in the Income-tax Rules, 1962, Part VII concerning payment of advance tax and prescribes the mandated form for service of such demand notices.