Confraternity of penitents

Confraternities of penitents (Spanish: Cofradía Penitencial; Italian: Fratellanza penitenziale; Portuguese: Irmandade Penitencial) are Christian religious congregations, with statutes prescribing various penitential works; they are especially popular in the Catholic Church. Members of the confraternities of penitents practice mortification of the flesh through fasting, the use of the discipline, the wearing of a hair shirt, among other instruments of penance, etc.

Source: Wikipedia — Confraternity of penitents (CC BY-SA 4.0)