Good question.
Always thought the nickname
Bill for
William was just odd and an unfortunate homophone with the kind of bill one pays.
Jack for
John. How, just how? For
Jacob possibly historically.
Bob for
Robert. Sounds like a kid with a stuffed up nose trying to say Mom.
Charlie is okay for
Charles. But what the
Chuck?
I agree with some others about
Eddie while
Edward is classy.
Don't care for
Dick for
Richard for obvious reasons.
Richard,
Rich or
Rick are okay.