Coarse animal hair generally refers to fibers from animals such as horses, yak (outer coat), camel (outer coat), and similar species whose fiber diameter exceeds the thresholds used to define 'fine' animal hair under the wool and fine animal hair headings. The chapter notes to Section XI provide the controlling definitions; when fiber diameter is borderline, laboratory testing may be required to confirm classification.

The heading explicitly covers yarn 'whether or not put up for retail sale,' so both industrial packaging and retail presentation fall here. Retail packaging does not shift the good to a different heading, though it may affect the applicable tariff rate at the 10-digit US tariff line level.