Heading 5606 covers chenille in yarn form — the pile-bearing strand before it is woven or knitted into a fabric. Once the yarn has been woven into a fabric, the fabric is classified under the appropriate woven fabric heading (such as chapter 54 or 55 for man-made fiber fabrics). Finished articles like upholstery or garments made from chenille fabric move further into chapters 57, 61, or 62 depending on the article type.

Heading 5605 specifically captures man-made yarn of 67 decitex or more combined with metal, whether or not gimped. Heading 5606 covers gimped yarn that does not meet the metal-combination criteria of 5605 — for example, a gimped yarn where the wrapping is purely textile with no metallic component, or where the dimensional thresholds of 5605 are not met. If a gimped yarn contains metal and meets the 5605 specifications, it belongs there rather than in 5606.