Expansion of tax incentive to include substantial renovation and modernisation of transmission or distribution lines, with specified exclusions. The amendment brings substantial renovation and modernisation of existing transmission or distribution lines within the scope of the tax incentive, revises cross references to include such undertakings, and excludes transfers of machinery or plant formerly used by a State Electricity Board from qualification. It defines substantial renovation and modernisation as an increase in plant and machinery in the network by at least fifty per cent of the book value as on the reference date and adjusts the relevant qualifying and transitional dates.