It always gets more interesting when a third language is involved. For instance, the source document - which you either don't have or have to specially request and wait for - mentions names in a third language, which uses a different writing system, and the names are obscure so you're never quite sure whether they've been transliterated according to source language or target language conventions. Or a mixture of both. The one that sticks in my memory though was not an obscure name but an everyday word. The original Polish document quoted someone in Russian, for some forgotten reason, and it had been translated as "In Russian we have the word człowiek, which... " Well, no, you don't have that word in Russian, because it's Polish! To put a Polish word in an English document and say it's Russian is absurd!