Sigma Theta Tau International Honour Society of Nursing recognises global nursing excellence. Sigma's mission is advancing world health and celebrating nursing excellence in scholarship, leadership, and service. Sigma's vision is to be the global organization of choice for nursing. In the spirit of President Tigges' Presidential Call to Action 2017-2019, we are seeking to connect, collaborate, and catalyse. Show people you support excellence in nursing with a Sigma Twibbon.