Sui Juris

Sui iuris, commonly also spelled sui juris (/ˈsuːaɪ ˈdʒʊərɪs/ or /ˈsuːi-/), is a Latin phrase that literally means "of one's own right". It is used in both civil law and canon law by the Catholic Church.

The term Church sui iuris is used in the Catholic Code of Canons of the Oriental Churches (CCEO) to denote the autonomous churches in Catholic communion:

A church sui iuris is "a community of the Christian faithful, which is joined together by a hierarchy according to the norm of law and which is expressly or tacitly recognized as sui iuris by the supreme authority of the Church" (CCEO.27). The term sui iuris is an innovation of the CCEO, and it denotes the relative autonomy of the oriental Catholic Churches. This canonical term, pregnant with many juridical nuances, indicates the God-given mission of the Oriental Catholic Churches to keep up their patrimonial autonomous nature. And the autonomy of these churches is relative in the sense that it is under the supreme authority of the Roman Pontiff.

In civil law, the phrase sui juris indicates legal competence, the capacity to manage one's affairs (Black's Law Dictionary, Oxford English Dictionary) as opposed to alieni juris, which means someone under the control of another, such as one adjudged incapable of appropriate self-determinations or an infant. It also indicates an entity capable of suing and/or being sued in a legal proceeding in its own name without the need of an ad litem. It also relates to customary, unique rights afforded to an individual unequal and exceptional, per feudal prerogative legal structures (that were additionally in personam and so legally reciprocal at the scale of personhood, effectively accruing constituencies polity by individuation).

...
Wikipedia