Our Constitution states:
ARTICLE II – BELIEF:
This Old Roman Catholic Communion is one in matters of Faith and Morals, de fide, with the Church established by Jesus Christ. It embraces all such doctrine of the Apostolic See of Rome, and it condemns all heresies and other errors condemned by that same See. It accepts as Catholics those who share this doctrine and conduct their affairs accordingly.
and also:
ARTICLE XXX – INTERCOMMUNION
SECTION 3. INTERCOMMUNION. — Members of this Communion may receive the Sacraments of Penance and the Holy Eucharist from priests whom they perceive to be Catholic as outlined in Article II (above) of this Constitution.
In practice we generally permit foreign clergy in valid orders to assist in choir, in choir dress, during sacred functions in our churches, and conduct ourselves in like manner in their churches.
Even with one another, we do not concelebrate in our tradition (except at one’s own ordination) so it removes a common point of friction.
We welcome any Catholic properly disposed to receive the sacraments. Our clergy enjoy friendships with Catholics of a variety of backgrounds including those who prefer the Mass of Paul VI. Though we only offer the sacraments according to the older rites.