If not fully understanding the "tails" explanation, tails means "reverse" on the coin,and heads means the "obverse". Every roll searcher wants a "heads/tails" roll. So one can determine what year and mint of that roll. It's great to find a roll (tails/heads) when one end is a certain variety. Nice premium then if you ever want to sell. In the 2009 Lincoln series,I have many nice end rolls with varieties on them!

