Define Political Correctness please?

Like that old bogus exam sheet that went around in the days before the internet:

1. You'll find a box under your desk containing caustic soda, pencil lead, water, and electric batteries. Create life, you have 45 minutes starting now.

So what is a workable definition of Political Correctness? I have come across two this week - one from Shadow Minister in Charge of Political Correctness Eradication Dr Wayne Mapp, which suggests possibly that an awful lot of my attitudes to life, and my lifestyle itself might be deemed Politically Correct, although I don't think that's what he means.

"Political correctness: a set of attitudes and beliefs that are divorced from mainstream values." (gleaned from today's Hard News)

And this from Camille Guy's rather timely radio review in the Listener this week, titled "PC Plod"

"In the course of the discussion, emeritus professor Elizabeth Gordon said that PC had become a lazy term of abuse for anything you did not like on the Left."

On the flipside, this photo implies that sitting with friends in a London "Gentleman's" Club (although the woman is the er... "member"), might qualify as Politically Incorrect.

So then, friends & visitors to SunnyO, whaddya reckon?