The newest dated quarters in my Type Set. 1906 Barber Quarter - NGC MS-63 1917 Standing Liberty Quarter/Type 1 - PCGS MS-64 FH 1923 Standing Liberty Quarter/Type 2/Variety 1 - PCGS MS-65 1929 Standing Liberty Quarter/Type 2/Variety 2 - NGC MS-64 1964 Washington Quarter - NGC MS-66
It's just my way of keeping track of what coins I've shown. Type Set 6.3: -- 6 is quarters -- .3 is the 3rd part (20th century coins)