Numismatic tails is a term used to describe the REVERSE side of a coin. It is also known as the 'tails side' or the 'back side' of a coin. The REVERSE side of a coin typically features a design or inscription that is different from the obverse side, which is commonly referred to as the 'heads side'. Numismatic tails are often used to identify coins and provide information about the coin's origin, denomination, and date of issue.