The surname, Duvall. In my hunts, I have found that name to be spelled in different ways. Examples: DuVall, DuVale, Duvalle, Duvall, Duval, On one occasion, it was spelled Deuel?
The one thing all those various spellings had in common, were they each came from France.
Thought it interesting too, depending on where 'they' had migrated to, seems to have had a role as to the spelling.