According to the KGB lexicon of intelligence terms[1] an Illegal (in Russian, a Nelegal) is a
“ | specially trained individual (an intelligence officer or agent) who lives under instructions from intelligence, and with the help of Intelligence, in a specified country with identity documents containing new assumed identifying particulars, generally in order to conceal from the authorities and the people around him his national and state affiliation, his true surname, and biographic particulars, thereby creating the conditions for conducting intelligence from illegal positions. | ” |
An Illegal Agent (Agent-Nelegal) is a
“ | specially selected and trained agent supplied by Intelligence with foreign identity documents with particulars selected from him, or obtaining such documents under instruction on his own and settling on the basis of these documents in a target country or a third country, in order to carry out intelligence assignments. | ” |
A Illegal Intelligence Officer (Razvedchik-nelegal) is a
“ | staff member of an intelligence service located on the territory of a target country and carrying out intelligence activity from illegal positions, under a false name, using forged identity documents relating to a citizen of the target country, a third country, or his own country, or concealing his actual presence in the country. | ” |