The long and short of it

Wiggle.co.uk advertised a pair of cheapish cycling shorts in size 16-18. I'm a reasonably solid size 18 in most clothes, but figured I'd risk it. They arrived yesterday so I tried them on this morning. They're a nice comfy fit. However they're labelled inside as a size 16 and on the cardboard tag as a size XXL. Is it any wonder people get confused over women's clothes sizes?