2006 North Dakota Quarter Cud

To me a die chip or Cud is a die stage, which makes it a "MINT ERROR." The die didn't look that (i.e. having a chip or Cud) before it started striking the very first coin. I would call it a form of die error. The die started having problems when striking planchets began. Thus, things like Cuds, die chip, die cracks, shattered dies, clashed dies, etc. are Mint errors, not die varieties or varieties. (Now a die could have been faulty but not visible to someone before striking, for example if it wasn't properly annealed or there were unseen impurities in the steel.)