NOC: Non-Official Cover (espionage)

I was actually looking for normal operation information on a Network Operation Central (NOC). But I came across this article explaining the espionage aspect of 'NOC'. Interesting stuff.

It is reserved for the situation where agents assume covert roles in an organization without ties to the government for which they work. Such operatives are named in espionage linguo as a NOC (pronounced "knock").

http://en.wikipedia.org/wiki/Non-official_cover