Page "Coin collecting" Paragraph 22

* Type collections: Often a collection consists of an examples of major design variants for a period of time in one country or region.

For example, Euro coins carry a " common side " that shows the denomination and a " national side " that varies in design from state to state within the Eurozone.

Likewise, a type collection might focus on an unusual design feature such as coins with a hole in the middle, coins that are not circular in shape or coins with brockage.