The primary distinction is garment length and coverage: a blouse or shirt (6106) covers the upper body only, while a dress (6104) extends to cover the lower body as well. A tunic-length top that extends well below the hip but does not cover the legs is generally still a blouse; CBP rulings on borderline lengths consider proportions and how the garment is marketed and worn.

Heading 6105 is specifically for men's or boys' shirts, while 6106 covers women's or girls' blouses and shirts. The garment's cut, sizing, and design features (such as darts, neckline styling, or sizing labeled for women) determine the correct heading. Unisex garments present the most difficulty; CBP guidance and prior rulings on unisex knit tops should be consulted for borderline cases.