Eucharist in the Catholic Church in the context of "Church tabernacle"

The Catholic Church has excommunicated some of its adherents throughout its existence for various reasons, including heresy, schism, and disobedience to the Church or its teachings.

In Roman Catholic canon law, excommunication is a censure and thus a "medicinal penalty" intended to invite the person to change behavior or attitude that incurred the penalty, repent, and return to full communion. Excommunication severs one from communion with the Church; excommunicated Catholics are forbidden from receiving any sacrament and refused a Catholic burial, but are still bound by canonical obligations such as attending Mass or fasting seasonally. Excommunicated Catholics, however, are barred from receiving the Eucharist or from taking an active part in the liturgy (reading, bringing the offerings, etc.).

An ostiarius, a Latin word sometimes anglicized as ostiary but often literally translated as porter or doorman, originally was a slave or guard posted at the entrance of a building, similarly to a gatekeeper.

In the Roman Catholic Church, this "porter" became the lowest of the four minor orders prescribed by the Council of Trent. This was the first order a seminarian was admitted to after receiving the tonsure. The porter had in ancient times the duty of opening and closing the church-door and of guarding the church, especially to ensure no unbaptised persons would enter during the Eucharist. Later on, the porter would also guard, open and close the doors of the sacristy, baptistry and elsewhere in the church.

In the Catholic Church, a Eucharistic congress is a gathering of clergy, religious, and laity to bear witness to the real presence of Jesus in the Eucharist, which is an important Catholic doctrine. Congresses bring together people from a wide area, and typically involve large open-air Masses, Eucharistic adoration (Blessed Sacrament), and other devotional ceremonies held over several days. Congresses may both refer to National (varies by country) and International Eucharistic Congresses.

On 28 November 1897, Pope Leo XIII proclaimed Saint Paschal Baylón patron of Eucharistic Congresses and Associations.