3. conference interpreting: (for national or international organisation) is the most prominent manifestation in our time.
It emerged during world war i when negotiations were held in french. But later on during the war some american and british negotiators did not speak french, which made official french-english bilingualism in the league of nations usher in de facto multilingualism in international conferences.

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military interpreting: Is when relations turn sour between two conflicting armed communities, as when it happens in talks with allies forces in during world war ii, truce negotiations or the interrogation of prisoners.