Class order is a bit of a stretch, but a only a real pedant would make a fuss

Maybe Mr Pedant...but surely you have heard of The Class Order of Mammals!!?

I've heard of the taxonomic ranks of animals, and am aware that the class "mammals" is split into three sub classes and a number of different orders. I didn't say 'class order' was wrong, just a bit of a stretch. There are other clues that would've rolled of the tongue a little easier I fancy.