A resident spy in the world of espionage is an agent operating within a foreign country for extended periods of time. A base of operations within a foreign country with which a resident spy may liaise is known as a "station" in English and a (, 'residency') in Russian. What the U.S. would call a "station chief", the head spy, is known as a () in Russian. Types of resident spies In the former Soviet Union and Russian nomenclature, there were two types of resident spies: (, legal resident spy) and (, illegal resident spy). In U.S. parlance, the same distinction is between "official cover" and "non-official cover". A legal resident spy operates in a foreign country under official cover (such as from his country's embassy). He is an official member of the consular staff, such as a commercial, cultural, or military attaché. He has diplomatic immunity from prosecution and cannot be arrested by the host country if suspected of espionage. The host country can expel such a person, requiring them to return to their home country as persona non grata. An illegal resident spy operates under non-official cover. They cannot claim immunity from prosecution when arrested. They may operate under a false name and have documents purportedly establishing them as a national of the country, or from a different country than the one for which they are spying. Examples of two famous Soviet "illegals" are Rudolf Abel, who operated in the United States; and Gordon Lonsdale, who was born in Russia, claimed to be Canadian, and operated in Britain. Other famous Soviet and Russian "illegals" include Richard Sorge, Walter Krivitsky, Vasily Zarubin, Alexander Ulanovsky, and Anna Chapman, who was also known as a sleeper agent. Comparison of illegal and legal resident spies The advantages and disadvantages of legal resident spies are generally the reverse of those for illegal resident spies. A legal resident spy has the advantage of diplomatic status, but the disadvantage of being a known foreigner to the host country and one of just a few official diplomatic staff. Their intelligence status may be easy for counterintelligence agencies to discern or suspect. On the other hand, an illegal resident spy has the advantage of being unknown as a foreigner to the host country, and one among millions of the country's ordinary citizens. The disadvantage is the lack of diplomatic immunity to fall back upon in case of