There is no acceptable definition of quality differences stemming from physical characteristics alone; the differences per tier also stem from branding, customer perception and retreadability.
Rapport concernant le différend Chine — Mesures imposant des droits antidumping sur les tubes, sans soudure, en acier inoxydable haute performance («HP-SSST») en provenance de l'Union européenne, WT/DS460/AB/R, paragraphe 5.180.