Swallows are always able to find their way home, which is why the swallow was a favorite tattoo for sailors who hoped to return home safely. The traditional swallow tattoo became a symbol for luck, noble intentions, hardships survived, and victory gained. For Katniss Everdeen, this was her mockingjay pin. It was given to her as a token of luck, and served as a reminder her promise to return home. Once she survived the Hunger Games, the mockingjay became a badge of victory.
Sailors often had two swallow tattoos to represent their freedom after a tour. And so, for Katniss and the people of Panem, two mockingjays would stand for hope and freedom from the Capitol.