The V for Voluntary symbol was created in 2007 in search for a new symbol that would capture the essence of the anarcho-capitalist movement and also carry a more positive message than other existing symbols.
The name is a play on the phrase 'V for Vendetta'. But where Vendetta stresses vengeance and violence, Voluntary stresses peace and looking forwards, not backwards.
The colors of the symbol are yellow (or gold) and black. Yellow is a reference to gold, which was the market chosen money. So it's a reference to free market money, and by extension the free market and capitalism. Black is a reference to anarchy. Anarchy, or an-anarchy, means no rulers. This means that no person should have forceful control over the life of another person.

The shape at the top of the symbol represents a handshake, which is the most typical expression of a voluntary agreement.
Own work
Nielsio