Welcome to the Lincoln Cent Forum Glossary.
Use the alphabetical links above to navigate to the desired term.
This glossary of terms was written and compiled by Will Brooks with the help of our forum members. A huge thanks to everyone who contributed knowledge, ideas, words, and photos to make this growing educational resource possible. Special thanks to Richard Cooper, aka “Coop” who donated many of the photos.
K Number: This is a number from 1-12 corresponding with a traditional clock face in order to identify an area on a coin face. Imagine a clock face super-imposed over a normally-oriented coin face. This system is useful for identifying the point of pivot when identifying class 5 doubled dies.
Key Date: The most difficult date/mint mark/variety in a coin-series to obtain due to rarity and expense. In the Lincoln cent series, the key date is the 1909S VDB. Some may also consider the 1909S, the 1914D, and 1931S as key dates, while others would consider these “semi-key.”