* ExecutiveMeddling: A minor example, but Creator/FredZinnemann and producer Sir John Woolf argued over whether the English cast members should speak with French accents. Woolf thought it would be distracting if French characters [[NotEvenBotheringWithTheAccent spoke like Englishmen]], while Zinnemann argued that if the movie was good enough [[MST3KMantra it wouldn't matter to the audience]]. Zinnemann won the argument, though he admitted afterwards that Woolf wasn't entirely wrong.
* FakeNationality: Most of the major French characters are played by English actors, though Creator/MichaelLonsdale, Delphine Seyrig and Olga Georges-Picot are exceptions.
* LifeImitatesArt:
** Infamous terrorist and assassin Ilich "Carlos" Ramírez Sánchez was given the nickname "The Jackal" after a Guardian correspondent saw a copy of this book among his possessions. Ironically the book didn't even belong to him, but to the person who owned the apartment where he was staying.
** Intelligence agencies have often come to refer to one of the ways the Jackal created a fake identity -- by using the name, along with birthdate and place of birth, of someone who died as an infant or small child -- as "the Jackal" system or method (the method existed before the book, but the book popularized it, or at least made people more aware of it - see the Shown Their Work entry on the main page).
* UncreditedRole: Creator/DavidKernan as Per Lundqvist.
* WhatCouldHaveBeen:
** Creator/JohnFrankenheimer wanted to direct.
** Creator/MichaelCaine, Creator/RogerMoore, Creator/JackNicholson and Creator/RobertRedford were all considered for the Jackal, but Creator/FredZinnemann refused to cast a star in the role, feeling that the character should be anonymous. Creator/RobertShaw lobbied for the part, but Zinnemann was looking for someone "nimble and willowy".
** Creator/FrederickForsyth was offered a a CreatorCameo as Charles Calthrop, [[spoiler:the man mistaken for the Jackal's true identity.]]
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