Canon 7
Neither clerics nor laymen should take communion in other churches without the letters from their bishop.
Cassianus, bishop of Usula, said: let your dignity order that no cleric or layman take communion in other churches without the letters from his bishop.
Bishop Gratus said: if this was not observed, there would be great confusion; but if he is accepted with the letters, the consent between bishops is preserved and nobody is escaping his own community in a subtle way, let him be happily accepted into another one.
All said: You provide for all, looking after both clergy and laymen.
(trans. S. Adamiak)