Interesting crumb from an older article about covers for CIA

"The vast majority of the agency’s overseas officers are under what is known as “official cover,” which means they are posing as employees of another government agency. The State Department allows hundreds of its positions in embassies around the world to be occupied by CIA officers representing themselves as diplomats.

A rarer and more dangerous job category is “nonofficial cover” — or “NOC” (pronounced knock) — in which CIA officers pose as employees of international corporations, as scientists or as members of other professions. Such covers tend to provide a plausible reason to work long periods overseas and come in contact with foreign nationals the agency wants to recruit."

https:// www.seattletimes.com/nation-world/cias-secret-agents-hide-under-a-variety-of-covers/