In a word, it represents typical Catholicism. Persons desiring to join must apply for membership in a praesidium. A praesidium numbers from six to twenty members. Praesidia are organized with the approval of the local curia. The praesidium may be for men only, for women only, or mixed, according to circumstances and needs.
Candidates have a three months' probation in which they perform all the prescribed duties.
Then they become full-fledged members by making the Legionary Promise to the Holy Spirit during the weekly meeting in the presence of the praesidium. Any member may be chosen as an officer and full obedience is given to the authority of the president approved by the spiritual director. The Legion is a lay apostolic group and the spiritual director remains behind the scenes as advisor and director, representing the clerical guidance required by Catholic Action, which is a sharing by the laity in the apostolate of the hierarchy. A member must be at least eighteen years old. However, there are junior praesidia for those between ten and eighteen, with duties befitting their abilities, under the direction of a senior Legionary.