What this coin looks like (obverse, reverse, mint mark location, special features, etc.): There are a number of various varieties of the 1836 Capped Bust Half Dollar. All varieties of this type still feature the lettered edge and the "50 C." denomination on the reverse of the coin (which would be redesigned later in the same 1836 year). This variety is depicted above.
There were a few overdate and repunch varieties during this year. The 1836/1336 overdate error is one of these varieties. This coin features an 1836 date struck over an 1336 date which resulted in parts of a "3" being visible within the bottom portion of the "8". This error was the result of an engraver recutting an "8" punch from a "3". Parts of the "1" and "6" in the 1836 date are also very subtly doubled. These features are depicted below in the example image of this variety:
Another repunch variety features a "50" struck over a "00" on the "50 C." denomination figure on the reverse of the coin. This can be identified by noticing parts of the underlying "0" being visible just to the left side of the "5" as depicted below in the example image:
Another variety features a beaded border on the reverse of the coin (Overton O-106 variety). The normal border has denticles that extend all the way to the outer rim and edge of the coin. The beaded border variety has a raised rim and the denticles only extend to the inner edge of the raised rim and the rim remains flat and smooth extending the rest of the way to the outer rim and edge of the coin - resulting in the denticles having a "beaded" look. The difference between the 1836 Normal Border vs Beaded Border half dollar is depicted below in the example comparison image of the coins: