Noils are the short fibers separated during combing of wool or fine animal hair and are classified specifically under 510310. Other waste under 510320 covers yarn waste, pulled or garnetted fiber residues that do not meet the garnetted-stock definition, and similar processing byproducts. The key distinction is whether the material results from the combing step specifically or from another stage of processing.

Garnetted stock — fiber recovered by mechanically shredding wool rags, yarn, or fabric — is explicitly excluded from heading 5103 and classified under its own heading (5104). If a material has been through a garnetting machine to reclaim fiber, it belongs there rather than here, even if it resembles loose wool waste in appearance.