What is the importance of tattoos in the novel, Allegiant?

Tris and most of the other Dauntless sport tattoos that mean something to them. Tris’s birds in flight show how free she feels living in Dauntless as opposed to Abnegation. It also represents her freedom to love and make the choice to sacrifice for them. It also represents her family, whom she deeply loves. Others, like Tori, get a tattoo of something that they formerly feared, but fear no longer.