Service tax exemption for upfront premium on long-term industrial plot leases; refunds available with a limited post-enactment claim window. Exemption applies to service tax on one-time upfront amounts charged by a State industrial development corporation or undertaking for grant of long-term leases of industrial plots of thirty years or more for the period 1 June 2007 to 21 September 2016, and refunds are required for tax collected that would not have been leviable; refund claims must be filed within six months from the date the Finance Bill, 2017 receives the President's assent.