O-Pe
Orthodox ― Pentecostal Academic Dialogue
OO-O
Eastern Orthodox ― Oriental Orthodox
OC-O
Mixed Old Catholic ― Orthodox Commission
O-RC
The Joint International Commission for Theological Dialogue Between the Roman Catholic Church and the Orthodox Church
O-R
Orthodox ― Reformed Bilateral Conversations
O-M
Orthodox ― Methodist Dialogue
L-O
The Lutheran ― Orthodox Dialogue
A-O
The Commission for Anglican ― Orthodox Joint Doctrinal Discussions