Firms also use fancy job titles to signal that they are au fait with the latest fashion.

ECONOMIST: Inflation in job titles is approaching Weimar levels

The report found that the CRU scientists would, had they been more statistically au fait, have done some things differently.

ECONOMIST: Climate science and its discontents: A place in the sun | The

But the hosts at my dinner party were not "Ossies" but "Wessies", completely au fait with bananas and even, perhaps, porcini.

BBC: Frugality rules at German dinner parties

Young people might now be totally au fait with social networking sites, but are not aware of all the techniques of more traditional networking.

BBC: Networking: Does everybody need to schmooze to get on?

Mr Sierra says that although the Colombian public may not be au fait with the Northern Ireland process, the politicians have followed it closely.

BBC: Can Northern Ireland act as a template for Colombia?

But it is more like a confused soap opera, overcrowded with characters and suffering from the constant desire to prove itself au fait with its cool surroundings.

ECONOMIST: Failure of imagination

What has Cameron done this time (and a slight correction for those not au fait with British politics: the budget is done by the Chancellor, George Osborne, not by the Prime Minister, David Cameron)?

FORBES: Britain's in Recession Again: But Delong and Krugman Really Shouldn't Chortle So

Nonetheless, the color grey which mainstream fashion has been flirting with for the past few years and now, thanks to the book, the mainstream Western World is unavoidably au fait with is the shade of the season.

WSJ: Tina Gaudoin on Style: Twenty Five Shades of You Know What��

If this was a social network or an online supermarket, it would perhaps be more of a major shock to the consumer base - many of whom would be less au fait with the realities of online content than console owners.

BBC: Sony crisis: The expert panel