Can. 444

§1. All who are called to particular councils must attend them unless they are prevented by a just impediment, about which they are bound to inform the president of the council.

§2. Those who are called to particular councils and have a deliberative vote in them can send a proxy if they are prevented by a just impediment; the proxy has only a consultative vote.

Read the whole title TITLE IIGroupings of Particular Churches 431–459