As a concession to current usage, my plays always include a first page which lists names under the heading "Characters," but it has never set well with me. "Persons in the play" might be a better description, or "roles," but definitely not "characters" which presupposes a reality behind the names, or the parts. (It may be part of an actor's technique to create a character, but certainly lies outside the purview of the playwright.)
As Montaigne said, Que sais-je?