A motu proprio is a papal document, written as a personal response from the Holy Father to questions or petitions from individuals or groups. It is meant to be written in the Pope's own hand (motu proprio literally translates to "in his own hand"), and in this way it differs from other more official papal documents, such as an apostolic constitution or a papal bull. Vos Estis Lux Mundior You Are The Light Of The World is the third motu proprio of Pope Francis' pontificate. It outlines rules established by the Church to fight sexual abuse and encourage accountability and transparency.