Правило 48
On the name of the bishop of the primacy see.
The bishop of the first see should not be called the exarch of the priests, or the supreme priest, or any similar name, but let him only be called the bishop of the first see.
Greek original
Ὥστε τὸν τῆς πρώτης καθέδρας ἐπίσκοπον μὴ λέγεσθαι ἔξαρχον τῶν ἱερέων, ἢ ἄκρον ἱερέα, ἢ τοιουτότροπον τίποτε, ἀλλὰ μόνον ἐπίσκοπόν της πρώτης καθέδρας.
Parallel canons
Ап.34IVВс.9Сард.6