Key date

In coin collecting, a key date refers to a date (or date and mint mark combination) of a given coin series or set that is harder to obtain than other dates in the series. The next level of difficult to obtain coins in series are often referred to as semi-key dates or simply semi-keys. For example, the 1909-S VDB is the key date in the Lincoln cent series. The 1914-D and 1931-S are considered semi-keys. In the United Kingdom £1 coins from 1988 are considered key date coins.

Key date

In coin collecting, a key date refers to a date (or date and mint mark combination) of a given coin series or set that is harder to obtain than other dates in the series. The next level of difficult to obtain coins in series are often referred to as semi-key dates or simply semi-keys. For example, the 1909-S VDB is the key date in the Lincoln cent series. The 1914-D and 1931-S are considered semi-keys. In the United Kingdom £1 coins from 1988 are considered key date coins.