Service tax exemption for port construction services removes tax on specified works carried out wholly within port premises. Exempts the taxable service of commercial or industrial construction provided wholly within a port for construction, repair, alteration and renovation of wharves, quays, docks, stages, jetties, piers and railways from service tax; the exemption is territorial in scope, limited to services provided wholly within a port, and was instituted by executive notification subject to later rescission.