11 You are aware that We are referring to the Instruction on Popular Christian Action which, by command of Leo XIII, the Sacred Congregation of Extraordinary Ecclesiastical Affairs issued on January 27, 1902, and which was sent to each one of you to carry out in your dioceses. For Our part, We maintain and, with the fullness of Our power, We renew these instructions with each and every one of their regulations. Similarly We confirm and renew all the orders We issued in the motu proprio of December 18, 1903, on Popular Christian Action along with the Circular Letter dated July 28, 1904, of Our beloved son, the Cardinal Secretary of State.
Source: Pieni L'Animo (Vatican.va)