From IMDb: ""Pop" Byron (born Aquilla Stewart Byron) always went by his initials "A. S." and never named himself "Arthur." Unfortunately, many readers, seeing "A. S.," wrongly assumed that those initials stood for "Arthur." They did not! Whenever you see a credit to "Arthur S Byron" or "Arthur (Pop) Byron," those are mistakes, and need to be rewritten as "A. S. (Pop) Byron," in order to refer correctly to Aquilla Stewart (Pop) Byron."