What this coin looks like (obverse, reverse, mint mark location, special features, etc.): There were two major versions of the 1823 Capped Bust Dime. Both of them actually have the date 1823 stamped on top of the 1822 date or an overdate error. The difference between the two varieties is in regards to the words "UNITED STATES OF AMERICA" on the reverse of the coin. One variety will have small letter "E"s in the words while the other variety will have large letter "E"s. There are three letter "E"s to look for when identifying the coin variety.
Below is a depiction of the 1823/2 overdate error where the 3 is stamped on top of the 2. A small part of the underlying "2" can be seen near the bottom of the "3". Most noticeable is a small "hook" sticking out from the bottom-right side of the "3" as depicted in the example image below: