The difference between a typical and non typical rack is that a typical rack ONLY has points that originate from the main beam and point in an upward direction where as a non typical has one or more points that originate from other points or points that originate from the bottom side of the main beam.
So a non typical buck can simply have a split brow tine or a small kicker off of one other point and technically it is a non typical deer.
I did not know that. I always assumed the deer had to have multiple drop tines or abnormal points growing from odd places.