CBP generally looks to commercial designation and design features. Blouses typically have styling associated with women's or girls' wear (e.g., decorative elements, fitted cuts), while shirts may have a more utilitarian construction. Both are captured under heading 610610, so the distinction within this heading is less critical than confirming the article is knitted, of cotton, and sized for women or girls rather than men or boys.

To support classification under 6106100020, importers should retain commercial invoices, packing lists, and product specifications showing that the blouse is presented and sold as part of a coordinated playsuit set. CBP may request evidence that the matching bottom garment is imported simultaneously and that the items are designed to be worn together.