Canon 156

1. Within three months after episcopal ordination or, if already ordained a bishop, after the enthronement, the metropolitan

is bound by the obligation to petition the pallium from the Roman

Pontiff, which is a sign of his metropolitan power and full communion of the metropolitan Church sui iuris with the Roman Pontiff. 2. Prior to the imposition of the pallium, the metropolitan cannot convoke the council of hierarchs or ordain bishops.