V sign.

From Wikipedia, the free encyclopedia

The V sign is a hand gesture in which the first and second fingers are raised and parted, whilst the remaining fingers are clenched, palm facing outwards. Originally considered a "Victory" sign (for V as in victory), it also is used to mean "Peace", a meaning that became popular in the United States during the peace movement of the 1960s.

The gesture has varying meanings depending on the context or culture.

"Victory" – the original meaning, sometimes using both hands, or upraised arms
"Peace" – Used by peace groups, counter-culture, from Chicago to Tiananmen Square
The number 2 – Used in noisy settings, as in a restaurant. Also ASL
The number 5 – Used in Roman Empire
"Time out" – Used in children's games

Ba careful so that you don't get it mixed up with when palm facing the signer it, according to wikipedia, means "Insulting". This is largely restricted to the UK, Ireland, Australia and New Zealand.