Sui generis
Sui generis (; ) is a Latin phrase that means "of its (his, her, their) own kind; in a class by itself; unique."
Sui generis
In political philosophy, the unparalleled development of the European Union as compared with other international organizations has led to its designation as a "sui generis" geopolitical entity. The legal nature of the EU is widely debated because its mixture of intergovernmental and supranational elements causes it to share characteristics with both confederal and federal entities. It is generally considered more than a confederation but less than a federation, thus being appropriately classified as an instance of neither political form. Compared to other international organizations, the EU is often considered "sui generis" because its legal system comprehensively rejects any use of retaliatory sanctions by one member state against another.