In the human intelligence game, they call such operatives NOCs, which stands for nonofficial cover.

Some are "nocs" (pronounced knocks) who operate under nonofficial cover, perhaps posing as an oil company executive in the Middle East.

Four were under diplomatic and one under nonofficial cover.

A much smaller number are under nonofficial cover or NOC (pronounced "knock").

As a covert operative who specialized in nonconventional weapons and sometimes worked abroad, she passed herself off as a private energy expert, what the agency calls nonofficial cover.

Because American sanctions ban most business and academic ties, infiltrating spies under what is known as nonofficial cover is difficult.

If there are separate organizations with diplomatic and nonofficial cover, there may be two chiefs.

His role was that of the "illegal" resident in the US, under nonofficial cover.

To deal with this threat, the agency has to have a majority, not just a small fraction, of its operatives abroad, operating under nonofficial cover.

I'm here on nonofficial cover.