JOHN BRENNAN has been nominated by Barack Obama to run the CIA. Many of the early articles about the nomination, and older ones about Mr Brennan's career, refer to him as a "spook". This, of course, is jargon for a "spy". But I suspect it's entirely journalistic jargon: while hacks use the term with a sort of knowing tone ("we're all habitués of the spook business here"), I imagine that spooks do not, in fact, call themselves spooks. (Professional spies, please feel free to let us know in the comments.)

One of the reasons is the nature of insider language itself. It's designed to be different from what outsiders use. People who work at the CIA frequently just call it "CIA", no definite article. Though in the popular parlance they are "CIA agents", CIA spies call themselves "officers", and use "agents" to refer to the foreign nationals they recruit to help them spy. Johnson reported earlier on a glossary of intelligence terms compiled by Stratfor, a private intelligence outfit, which was leaked. But who knows if Stratfor really got the real inside spook-speak? As the glossary says, "Anyone who tells you about a black op is a liar." Surely that goes for much of the cant that makes up spy language.

I'd imagine "spook" is like a lot of words outsiders use but insiders ignore or hate. Nobody in New Orleans (besides perhaps the tourist board) really calls the city the "Big Easy", just as people in San Francisco hate the nickname "Frisco". I've never heard my IT department refer to a "computer" (it's a "machine", of course). Computer programmers aren't "programmers" and they don't "program": they're coders who code. I've never heard a journalist refer to an "article"; we write "pieces". 

I'm sure readers can think of many more examples.