Quote:Repunched Mint marks: Mint marks were punched into each individual working die (for coins issued for circulation) by hand with mallet and punch, before changes were made to the process in 1990 and 1991. Under the old system, several blows to the punch were needed to properly sink the Mint mark into the working die. If the punch was not properly placed after the first blow, a multiple image could result. A coin identified as a 1960-D/D
Lincoln Cent has a repunched D Mint mark, for example. Coins with RPMs are die varieties. Most RPMs carry low premiums.