Cotton Subheading Note. 1.- For the p oses of subheadings 5209.42 and 5211.42, the expression "denim" means fabrics of yarns of d2erent colours, of 3-thread or 4-head twill, including broken twill?warp faced, the yarns of which are of one and the same colour and the weft yarns of which are unbleached, b l e a o z dyed grey or coloured a lighter shade of the colour of the warp yarns. GENERAL The General Explanatory Note to Section XI should be taken into account in reading the Explanatory Notes to this Chapter. In general, the Cha ter covers cotton fibres at the various stages of their conversion fiom raw material to woven abrics, and includes mixed textile materials classified as cotton. P