The supreme pontiff’s words: "I wish especially to make an appeal both solemn and heartfelt, paternal and fraternal, to all those who until now have been linked in various ways to the movement of Archbishop Lefebvre, that they may fulfill the grave duty of remaining united to the vicar of Christ in the unity of the Catholic Church
and of ceasing their support in any way for that movement. Everyone should be aware that formal adherence to the schism is a grave offense against God and carries the penalty of excommunication decreed by the church’s law" (Ecclesia Dei 5c).[emphasis added]
Pretty clear, eh?
""By virtue of my Apostolic Authority I Decree ... respect must everywhere be shown for the feelings of those who are attached to the Latin liturgical tradition, by a wide and generous application of the directives already issued some time ago by the Apostolic See, for the use of the Roman Missal ... of 1962."(Ecclesia Dei)
Pretty clear, eh?