Ad valorem exemption limits excise duty on specified tariff items to the stated rate, with listed entries treated as nil. Notification exempts specified tariff entries from excise duty to the extent that duty exceeds the amount computed at the listed ad valorem rate. Issued under section 5A(1) of the Central Excise Act, the notification lists certain Chapter, heading or sub heading numbers with the applicable rate stated as nil and explains that rates are ad valorem unless otherwise indicated; the notification was later rescinded.