6105.90.80.30 - Subject to man-made fiber restraints (638)

This HTS category, 6105.90.80.30, specifically covers men's or boys' shirts that are knitted or crocheted, and are manufactured from "other textile materials." This designation applies when the shirts are subject to specific man-made fiber restraints as indicated by the quota number (638). These restraints are crucial for determining the correct classification and compliance with import regulations.

It is important to distinguish this category from its siblings. While all fall under men's or boys' knitted or crocheted shirts of "other textile materials," the critical differentiator here is the presence of man-made fibers subject to restraints. For instance, 6105.90.80.10 covers similar shirts but is subject to cotton restraints, and 6105.90.80.20 pertains to those under wool restraints. The category 6105.90.80.60, also under "other textile materials," serves as a residual category for items not falling under specific fiber restraints like cotton, wool, or the man-made fibers covered here.

As a leaf node, this classification does not have further subdivisions. Therefore, the precise identification of the "other textile materials" as being man-made fibers under restraint is the sole determinant for goods classified under 6105.90.80.30. This includes a wide array of synthetic and artificial fibers, such as polyester, nylon, acrylic, and rayon, provided they are knitted or crocheted into a men's or boys' shirt and fall within the designated quota limitations.