Chances are you have seen Star Wars: The Last Jedi, the biggest box office hit of 2017. Among the characters in this one is DJ, an opportunistic hacker played by Benicio Del Toro. "DJ" is not his initials, though, it stands for "Don't Join" -- his motto, as in he doesn't choose sides. IGN notes, via the new book Star Wars The Last Jedi The Visual Dictionary, that the name was inspired by a promotional poster for Elvis Costello's Armed Forces that you can see above. "I always loved that phrase," says the film's writer and director, Rian Johnson.

Meanwhile there were some pop stars in The Last Jedi, too, as Ellie Goulding, and Take That's Gary Barlow had uncredited cameos, as did director Edgar Wright, Joseph Gordon Levitt, Prince William and Prince HarryTom Hardy, and others.