MI6

Abbreviation for Military Intelligence, Section 6 and a common name of Britain’s intelligence agency, the Secret Intelligence Service (SIS). MI6 is an almost interchangeable title for the SIS which originated in the late 1930s, when it was adopted as “a flag of convenience” for the SIS. Although the term “MI6″ fell into official disuse years ago, it is still used by many writers and journalists to describe the SIS.