It is limited to liberal and radical egalitarian parties with substantial support, mainly proved by having had a representation in the parliament.
In Denmark liberalism became a dominant force in 1840, but developed into a conservative direction.
Thus it refers to an old left/right division of the political scale, in modern terms Venstre is usually considered a right wing party and Det Radikale Venstre as a centre party.
[1] Below is a timeline listing the name changing and history of the political parties centred on the idea of liberalism in Denmark.
Confusingly the term 'left' is used in the name of some liberal parties in Denmark for historic reasons.