Flax, true hemp (Cannabis sativa L.), and ramie are all excluded. Yarn of those fibers classifies under their own dedicated headings. Heading 5307 captures jute and all other textile bast fibers not covered elsewhere in the chapter.

The heading divides by construction: single yarn (530710) versus multiple (folded) or cabled yarn (530720). Twist level within a single yarn does not change the subheading, but the number of plied strands does. Cabled constructions — where multiple plied yarns are twisted together — fall under 530720 regardless of the final twist direction.