covert agent
(4) The term “covert agent” means— (A) a present or retired officer or employee of an intelligence agency or a present or retired member of the Armed Forces assigned to duty with an intelligence agency whose identity as such an officer, employee, or member is classified information; or (B) a United States citizen whose intelligence relationship to the United States is classified information, and— (i) who acts as an agent of, or informant or source of operational assistance to, an intelligence agency, or (ii) who is at the time of the disclosure acting as an agent of, or informant to, the foreign counterintelligence or foreign counterterrorism components of the Federal Bureau of Investigation; or (C) an individual, other than a United States citizen, whose past or present intelligence relationship to the United States is classified information and who is a present or former agent of, or a present or former informant or source of operational assistance to, an intelligence agency.