Auction - Mileage: N/W

[lethologica]

I'm going to a car auction tomorrow morning and have been looking at the lot order this evening.  Under mileage, for many of the cars it gives a mileage and then has either W or N/W next to it.

I'm guessing this means verified or non verified, but what does the W stand for!?

Any help before bed appreciated!!

[v64paul]

w stands for warranted, the mileage is either verified as genuine or not.