Unlike most apparel categories, where knit and woven constructions are separated at the heading level, brassieres are grouped by garment function rather than fabric construction. This reflects the trade classification logic that the specialized supportive function of the garment is the defining characteristic. The knit-versus-woven distinction still matters at the HTS subheading level for duty purposes, but it does not split the heading.

Sports bras are generally classified as brassieres when they provide breast support as their primary function, even if they lack underwire or traditional bra construction. If the article more closely resembles a crop top or athletic vest with only incidental support features, it may be classified elsewhere. CBP applies a principal-use and essential-character analysis; importers handling high volumes of sports bras should consider seeking a binding ruling to lock in the classification.