Query N operator

Hello,

I often see the N operaator before parameeter Query values, when I debug a queryrun in Dynamics Ax.

_queryRun {: SELECT * FROM ItemRequest(ItemRequest) WHERE ((Limited = 0)) AND ((ItemId = N'00052116')) AND ((InventLocationId = N'03460682_066'))} Dynamics.Ax.Application.QueryRun

What do they mean?

Thanks,
Karl