What would be listed if there was not comma...

I would think just a last name, or possibly a company name, or possibly
a mistake (in which case an error return would be appropriate).

What I posted would work for a last name only, not sure how you would
distinguish a mistake over a last name only (unless you meant that was the
mistake), but a company name has interesting consequence. Ford Motor Company
would work fine, but a little bit more problematic would be Apple, Inc.

Rick