List of excommunicable offences in the Catholic Church
This is a list, in chronological order, of present and past offences to which the Catholic Church has attached the penalty of excommunication; the list is not exhaustive. In most cases these were "automatic excommunications", wherein the violator who knowingly breaks the rule is considered automatically excommunicated from the church regardless of whether a bishop (or the pope) has excommunicated them publicly. However, in a few cases a bishop would need to name the person who violated the rule for them to be excommunicated. Excommunication is an ecclesiastical penalty placed on a  person to encourage the person to return to the communion of the church. An excommunicated person cannot receive any sacraments or exercise an office within the church until the excommunication is lifted by a valid authority in the church (usually a bishop). Previously, other penalties could also be attached. In cases where excommunication is reserved for the apostolic see, only the bishop of Rome (the pope) has the power to lift the excommunication. Before 1869, the church distinguished "major" and "minor" excommunication; a major excommunication was often marked by simply writing, "Let them be anathema" in council documents. Only  offences from the 1983 Code of Canon Law still have legal effect in the church. Council of Basel–Ferrara–Florence (1431-1445). Since theological historians have doubts about the ecumenical character of council sessions, the session number and location of each ruling are included: 1917 Code of Canon Law. The first unified code of canon law was produced in 1917, and it replaced all previous rules regarding excommunication which had come from councils and papal documents. The 1983 Code of Canon Law replaced the 1917 code. Therefore, only the 1983 code still has legal standing with regard to excommunicable offences . 1983 Code of Canon Law. Canon 1324 includes a number of exceptions from excommunicable offences: According to Canon 1329, unnamed accomplices may receive the same penalty when an excommunicable act is committed.