What one word was intentionally left out of the movie version of Mario Puzo's novel 'The Godfather' even though this word was the working title of the book?

Mafia, as odd as it may seem

When the adaptations were being made for the movie, someone also made a deal with the writers there that the word "mafia" must not be included in the script. It was never going to be in the script anyway...

"Cosa Nostra" and "Mafia" were both banned from the first Godfather film.

"Similar themes from the original are carried over and arise in Part II: revenge, intrigue, betrayal, alliances, violence, the corruptive influences of power, and devoted loyalties to the family. Unlike the first film, the forbidden words "Mafia" and "Cosa Nostra" are each mentioned once - in one of the Senate Hearings scenes."


http://www.filmsite.org/godf2.html