In a traditional Danish New Year's Eve custom, people smash plates against friends' doors.
The broken crockery is left outside a home as a symbolic sign of friendship and goodwill. A large pile of broken plates was traditionally interpreted as evidence that the household had many friends who visited or participated in the custom.
The practice belongs to a wider group of European New Year's traditions involving noise, breakage, or the removal of old objects. The exact form and popularity of the custom have varied over time, and modern celebrations are often less destructive than older descriptions suggest.
The item is sometimes mistakenly reported as glasses, because glassware is also used in New Year's toasts. In the Danish door tradition, however, the characteristic object is plates or other crockery.