Canon VI.
The Seventh Ecumenical Council (Nicaea II, 787) · The Seven Holy Ecumenical Councils
Since there is a canon which says, twice a year in each province, the canonical enquiries shall be made in the gatherings of the bishops; but because of the inconveniences which those who thus came together had to undergo in travelling, the holy fathers of the Sixth Council decreed that once each year, without regard to place or excuse which might be urged, a council should be held and the things which are amiss corrected. This canon we now renew. And if any prince be found hindering this being carried out, let him be excommunicated. But if any of the metropolitans shall take no care that this be done, he being free from constraint or fear or other reasonable excuse, let him be subjected to the canonical penalties. While the council is engaged in considering the canons or matters which have regard to the Gospel, it behoves the assembled Bishops, with all attention and grave thought to guard the divine and life-giving commandments of God, for in keeping of them there is great reward; because our lamp is the commandment, and our light is the law, and trial and discipline are the way of life, and the commandment of the Lord shining afar giveth light to the eyes. It is not permitted to a metropolitan to demand any of those things which the bishops bring with them, whether it be a horse or any other gift. If he be convicted of doing anything of this sort, he shall restore fourfold.
Nic2 10.6.3
Whenever it is not possible for a synod to meet according to the decree formulated long ago, twice in each year, at least let it be held once, as seemed good to the Sixth Synod. Should any magistrate forbid such meeting, let him be cast out: and a bishop who shall take no pains to assemble it, shall be subject to punishment. And when the synod is held, should it appear that the Metropolitan has taken anything away from any bishop, let him restore four-fold.
Nic2 10.6.6
Anastasius remarks on this, that this ordinance (whether the whole canon or only its last passage must remain undecided) was not accepted by the Latins. That this canon did not forbid the so-called Synodicum, which the metropolitans had lawfully to receive from the bishops, and the bishops from the priests, is remarked by Van Espen, l. c. p. 464.
Nic2 10.6.8