Goods classification under tariff headings determines duty liability by applying HSN-based rules and essential-character principles. Classification under the Central Excise Tariff requires determining the correct tariff heading and rate following HSN principles, applying Section and Chapter Notes first, then interpretative rules: include incomplete or mixed goods that retain the essential character (Rule 2), prefer the most specific description (Rule 3(a)), classify by the component giving the essential character (Rule 3(b)), fall back to the last-listed heading if needed (Rule 3(c)), or classify by analogy (Rule 4); special rules govern containers and packing (Rule 5) and subheading comparisons are confined to the same level (Rule 6).