Then, there's the tail. One benefit of a docked tail, for those who wish to have a guard dog, is the dog is harder to read. We who know dogs pretty well know that a wagging tail does not always mean friendly or happy; but I think most people think it does.
I remember on the street I used to live on, there was an older man who never talked to us much. One day he was walking down the street as Oji and I were in our front yard. Oji was looking at the man. The man said to me "I can't tell what he's thinking 'cause I can't see the tail!"
Incidentally, this is one major thing I'm thinking of as I am considering getting a different breed next time. The Cane Corso, for example, gets a longer crop. I don't like it, not only aesthetically, but because you can easily see it wagging. Often it's way way too waggy in the breed and it just looks terrible in addition to sending a "friendly" message that I don't want.