A personal ordinariate, often called a "personal ordinariate for former Anglicans" or more informally an "Anglican ordinariate", is a canonical structure within the Catholic Church established in accordance with the apostolic constitution Anglicanorum Coetibus of 4 November 2009 and its complementary norms. The ordinariates were established in order to enable "groups of Anglicans" to join the Catholic Church while preserving elements of their liturgical and spiritual patrimony. They are juridically equivalent to diocese, "a particular church in which and from which exists the one and unique Catholic Church," but may be erected in the same territory as other dioceses "by reason of the rite of the faithful or some similar reason."