1989 Half Dollar May Be DDO?

Die Deterioration and metal flow separation. Notching does not automatically mean doubling. There has to be a size increase from normal states and a shifting movement. There will be a slight if not bold separation line very similar to the effect a tilted RPM has on vertical bars and serifs on a mintmark. Remember the DDO is formed by hubbings die processes, not by mechanical motion effect, which includes die stresses, shifting movement impacts, and the like.