Customs tariff amendments revise rates and substitute tariff entries, altering drawback and excise classifications under amended notification. The Central Government, under statutory powers and Drawback Rules, substitutes and revises tariff item entries, descriptive headings and columnar duty/drawback figures in the Schedule to Notification No.103/2008-Customs (N.T.), effecting replacements across Chapters 52, 54, 60, 82 and 87, including specific polyester yarn classifications with an explanatory definition of 'manufacture of filament yarns', with effect from the first day of September, 2008.