Substitution of statutory reference clarifies that First Schedule means its pre-Act form, effective on Act commencement. The notification substitutes references to the First Schedule to the Central Excises and Salt Act, 1944 with the phrase that such references mean the First Schedule as it existed immediately before the commencement of the Central Excise Tariff Act, 1985, and stipulates that this amendment takes effect on the date the Tariff Act commences.