This standard describes two methods of indicating the composition of yarns, whether single, plied (folded), cabled or multiple wound. The notation comprises linear density indicated in the Tex System, number of filaments in filament yarns, direction and amount of twist, and number of plies (folds).

This standard does not apply to some special kinds of yarns, for example to fancy yarns, textured or bulked yarns or yarns produced by wrapping a textile or non-textile material round a core; nor does it deal with other features such as constituent fibers, after-treatment and type of package.