Manual of religious instruction usually arranged in the form of questions and answers and used to instruct the young, win converts, and testify to the faith. The medieval catechism concentrated on the meaning of faith, hope, and charity. Later catechisms added other subjects and became more important following the Reformation and the invention of the printing press. Martin Luther's Small Catechism (1529) added discussions of baptism and the Eucharist. John Calvin published a children's catechism in 1542. The Anglican catechism is included in the Book of Common Prayer. The Baltimore Catechism (1885) is the Catholic catechism best known in the U.S. In 1992 the Vatican issued a new universal Catechism of the Catholic Church.