 When Ford and Zaphod first greet each other on the Heart of Gold,  Zaphod calls Ford "Ix" and then quickly corrects himself. In the  novel, "Ix" was a nickname that Fords childhood schoolmates gave  him, which, according to the book, translates as "boy who is not  able satisfactorily to explain what a Hrung is, nor why it should  choose to collapse on Betelgeuse Seven."