Sui generis
A similar case that led to the use of the label "sui generis" is the relationship of New Caledonia relative to France, because the legal status of New Caledonia can aptly be said to lie somewhere between a French overseas collectivity and a sovereign nation. Although other examples of such status for other dependent or disputed territories may exist, this arrangement is unique within the French realm.
Suum cuique
The Latin phrase relates to an old Greek principle of justice which translates literally into English as "to each his own". Plato, in "Republic", offers the provisional definition that "justice is when everyone minds his own business, and refrains from meddling in others' affairs" (Greek: "...τὸ τὰ αὑτοῦ πράττειν καὶ μὴ πολυπραγμονεῖν δικαιοσύνη ἐστί...", 4.433a). Everyone should do according to his abilities and capabilities, to serve the country and the society as a whole. Also, everyone should receive "his own" (e.g., rights) and not be deprived of "his own" (e.g., property) (433e).