<h1>Textile classification rules: material predominance and specific yarn and product-form definitions determine tariff headings and scope.</h1> Section XI sets a classification framework for textiles and textile articles, listing specific exclusions and prescribing that multi-material goods be classified as wholly of the textile material predominating by weight or, if equal, by the heading last in numerical order. Composite yarns may be treated as a single material by aggregate weight; Chapters 54 and 55 can be treated as one. Detailed technical definitions apply to yarns treated as twine/cordage, retail put-up criteria, sewing thread, high tenacity yarn, and 'made up' goods, and sub heading notes define unbleached/bleached/coloured yarns and fabric types.