Fabrics containing 85% or more by weight of a specific synthetic filament (nylon, polyester, or other) fall under the dedicated fiber-type subheadings (e.g., 540741–540774). Fabrics below that threshold that are mixed mainly with cotton go to the 540781–540784 group, while other mixed fabrics fall under the 540791–540794 residual group.

Woven fabrics constructed from synthetic strip or similar flat forms — rather than conventional round-cross-section filament yarn — are specifically captured under 540720, which is distinct from the high-tenacity yarn fabrics at 540710 and the general filament-yarn fabric subheadings.