Atypical Die Clashes (ADC):

 1) Unusually strong clashes. 2) Multiple, staggered clash marks (3 or more sets). 3) Horizontally misaligned clash marks (10% or more). 4) Vertically misaligned (tilted) clash marks. 5) Rotated die clash (30 degrees or more) and 6) Pivoted die clashes.  Also included:  Clashes associated with cuds, clashes associated with rotated die errors (even if the clash itself is not rotated), clashes associated with misaligned die errors (both horizontal and vertical), clashes on weakly-struck coins, clashes on very strongly struck coins (fins, etc.) and any other case where a clash is associated with a press malfunction other than a feeder malfunction (the latter being off-center strikes, brockages, etc.) and type 1 counter clashes.  7) IS NOT another type of clash such as a MAD clash or a Counterclash (and remember: ADC & TDC do not mean MAD clash – they are not the same).  

What determines if a die clash is atypical or typical? 

The process is subjective in nature since it is based on the decisions of the authors of this site.  The prospective die clash is weighed against other die clashes that have been found in the denominational series and not weighed against all die clashes