29 This conciliatory policy with regard tocommunicatio in sacris(participation in things sacred) with the brethren of the separated Eastern Churches is put into the care and control of the local hierarchs, in order that, by combined counsel among themselves and, if need be, after consultation also with the hierarchs of the separated churches, they may by timely and effective regulations and norms direct the relations among Christians.
Source: Orientalium Ecclesiarum (Vatican.va)