I could look for a web site; I could try to track down the movie.

What I *do know:

A) They weren't talking just straight Diné Bizaad, which had no words for such things as P-38 or 100 pound bombs (e.g.) anyway. They used different kinds of birds to refer to different kinds of airplanes and bombs were eggs, for example. This doesn't sound to this miserable Fool like any sort of unbreakable code but.

2) The Germans, although they had studied American Indian languages extensively, had never studied Navajo or, apparently, the closely related Apache languages. Thus they had no information to share with the Japanese to help them understand what was going on.