Both width and height are used, but width seems to be the "official" term. It's difficult to confuse what the thickness is though :thumbup:
They should be the same, yeah. I remember reading somewhere that Busse assigns names to specific thicknesses. Anorexic is 0.15, regular is 0.22... I forget what else there was. I don't know if that's canon or if that's coincidental observation though.