What this coin looks like (obverse, reverse, mint mark location, special features, etc.): There were multiple varieties of the 1812 Capped Bust Half Dollar. The most common variety is simply the normal date without any errors or special features. The two major varieties feature the 1812/1 Overdate error resulting from an 1812 date struck over an 1811 date which resulted in parts of an underlying "1" being seen around the "2". There were two varieties of this - One had a small "8" and the other had a large "8". The comparison image of the small 8 vs large 8 varieties are depicted above in the example image.
The other very rare and valuable variety deals with the reverse of the coin. This variety contains only a single leaf on a branch just under the eagle's wing. Typically there are two leaves located here. This single leaf is the resulted of a lapped die and is extremely rare: