They are referring to this Canonical term: “sui iuris”, which in English has been translated in slightly various ways including:
“of its own law”, “of its own right”, “autonomous”, “self-governing”
It means that Eastern and Oriental Catholic Churches are governed by their own general law authorized by the Pope of Rome known as the Code of Canons of Oriental Churches, as well as, by their own particular laws that are not contradictory to this Code.
The Latin Church, which has the Pope as her Patriarch, and Bishop of her Prime diocese: Rome, is governed by its own Code of Canon Law.
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