Hi Rossim,
I originally thought the same thing but, if that is the case, then "posh" is in the wrong place as it comes after "Nancy" which doesn't make sense. U for "posh" is such a common occurrence in cryptics but I never knew the origin until Snowwhite pointed out that the term was coined by Nancy Mitford (another family that crops up with some frequency). The fact that Nancy is also often used to denote a French answer is doubly confusing!