Canon 104

1. All bishops legitimately called to the synod of bishops of

the patriarchal Church are bound by the serious obligation to

attend that same synod except those who have already resigned

from office. 2. If a certain bishop considers himself to be

detained by a just impediment, he is to submit his reasons in

writing to the synod of bishops of the patriarchal Church. The

bishops who are present in the designated place at the first

session of the synod are to decide upon the legitimacy of the

impediment.