Some markers happen because of the same events happening over and over. Clashes, cleanings, die cracks/chips/breaks. Bit if you look very closely the die crack may be in a different direction that may be from a different die. First you need to determine if the variety exists on your coin. Second check to see if markers match known die states. Some markers come and go during the dies life. Markers on fields can flatten with time and eventually disappear. Cracks and breaks only get worse with continued use. To look for a marker first is to search for a car with a dented fender and assume it is a rare car. Thing happen during a dies life, over and over, thus the reason for thought: A marker may or may not be present on all coins from a certain die. Just depending on the marker and how soon the die received that marker. Hope this helps?