The Lincoln Cent Error Coin Guide for 2020 includes the latest auction results and additions to errors. There are five types of error classifications and variations described in detail in this guide. - Doubled dies - Re-punched mint marks- Off-center errors - Planchet errors - clips and wrong planchet strikes - Mint striking errors - double strikes, die caps, brockage, bonded, and much more. - Variations - Variations are not actual errors but intentional deviations from the original design intent. Even with the US Mint having the best technology for producing billions of Lincoln cents, there are still modern-day errors in circulation. The wear and tear on the dies, the reworking of the dies, and malfunctions in the minting process create a multitude of mint errors that escape detection.