Definition of bus body building now includes building on chassis of Chapter 87 vehicles, with retrospective application. The notification inserts an Explanation to Notification No. 11/2017-State Tax (Rate) clarifying that the term 'bus body building' includes building a body on the chassis of any vehicle falling under Chapter 87 of the First Schedule to the Customs Tariff Act, 1975, and states that this amendment is deemed to have come into force from the specified earlier date.