6109.90.80.20 - Of wool (438)

This HTS classification, 6109.90.80.20, specifically covers women's or girls' knitted or crocheted t-shirts, singlets, tank tops, and similar garments made from textile materials other than cotton, synthetic fibers, or artificial fibers. The inclusion of "Of wool" within the description indicates that garments falling under this subheading are predominantly composed of wool. This designation is crucial for customs purposes, distinguishing these items from those made of other textile materials or those specifically designed for men or boys.

Within the broader category of "Other" women's or girls' knitted or crocheted garments not of cotton, synthetic, or artificial fibers, this subheading serves to isolate wool-based items. The sibling category, 6109.90.80.30 ("Other"), would encompass garments made from other miscellaneous textile materials not otherwise specified, such as silk, linen, or animal hair other than wool, for this particular gender and garment type.

As this is a leaf node, there are no further subcategories. Therefore, the classification relies on accurately identifying the garment type (t-shirt, singlet, tank top, etc.), the knitting or crocheting method of manufacture, the intended gender and age group (women's or girls'), and the primary material content being wool. Proper declaration of the fiber content is paramount to ensure correct entry under this specific tariff item.