Women's clothes are totally worse than kids even! I had one reputable ladies clothing store tell me quite cheerfully that their "Miss Big" range sizes were actually approximately a full size larger than those labelled in their regular range (so a 14 in the big girl range would actually be a 16-18 in regular) - to make women feel better about themselves of all things.
Umm, no it doesn't, not when we go to try on the 14 in the regular range and it doesn't fit!
