I refer of course to the former royal couple, Kate & Wills.
This article talks about how Kate wasn't posh enough for the B.R.F.1
She went to Marlborough FFS! That's posh enough for most people. The thing is the B.R.F. aren't just posh - they have taken it to whole new levels. Use of archaic English is a marker - apparently the use of words like "toilet" and "pardon" mark you down as common (I'm not sure how "shithouse" and "you what mate?" fit on this scale?). I personally would see this as indicative of a psychiatric disorder..
1. British Royal Family