Abatement extension for port and airport services expands eligible service categories, widening notified tax concessions. The notification amends the principal service tax abatement schedule by substituting additional classification identifiers into specific table entries so that services provided within ports, airports and other ports falling under the newly inserted categories become eligible for the abatement; a corrigendum corrected an omitted item in the original amendment and the changes operate from the stated effective date under the Finance Act empowering provision.