1690 6/5 PCGS AU 55 William Mary 4P Error Groat Great Britain England Silver Coin POP 2/0 (26021102C)Almost Uncirculated William & Mary England (Great Britain) silver 4 pence or groat sterling silver coin. Very rare date mint error variety where the "6" is a correction punched over a "5" erroneously installed by the die sinker. The lower curvature of the 5 can be seen within the circle on the 6. This should not be confused with an overdate which is an intentional effort to modify a date, such as 1691 over 1690, to preserve the usefulness of the die.