A special ‘blue book’, called “DOCAT”, and an application program (DOCAT app) has been released for the World Youth Day 2016’s pilgrims. DOCAT, an official Social Doctrine of the Catholic Church for the young people, is a result from 26 authors whose team directed by Cardinal Christoph Schönborn of Vienna and Cardinal Reinhard Marx of Munich-Freising. DOCAT elaborates the basic principles of the Catholic Social Teaching from 14 Papal documents since Rerum Novarum until Laudato Si in 12 chapters, mostly on practical issues in our social life, such as the basic principles of Social Teaching (common goodness, personality, solidarity, subsidiarity), various issues regarding the human community (family, society, international community), various social practical issues (economic life, political community, environment) as well as fundamental dimensions of social behaviour (work, social mission, peace, social involvement), and also some recent yet concrete "digression" topics, such as: bioethics, new media, poverty, goods belonging to the world community, freedom of research and its possible miss use, preservation of creation, fair trade, migration. Written yet developed in the same path as YOUCAT book, DOCAT has an urgency and importance for the whole Church and its young people as it reflects the personal wishes of the Holy Father to have “one million young people, even better, a whole generation who are for their contemporaries “walking, talking social doctrine“, to reaffirm that Christianity is a revolution of love and justice, and to reiterate the common goal of the Christian is to work towards building a “civilisation of love”. DOCAT respectedly could be a simple manual to assist the young people to be more rooted in faith, in works of mercy, also as another tool of New Evangelization to start a revolution of love and justice by knowing and doing social doctrine. By using the DOCAT app, YOUCAT Foundation probably would like to approach and encourage the young people to get involved in this “revolution” by saying “Yes, I do!” to this movement. As a starter, YOUCAT Foundation also arrange a “200 Project” which gathered 200 young people from few countries to promote the DOCAT and its tagline “One Million for the Pope” during the World Youth Day 2016 in Krakow and urge the young people from all over the world to get involved. This article will elaborate recent development on DOCAT movement in some countries; especially some countries which its young people took participate in the “200 Project”.