Sui generis
In local government, a "sui generis" entity is one that does not fit with the general scheme of local governance of a country. For example in England, the City of London and the Isles of Scilly are the two "sui generis" localities, as their forms of local government are both (for historical or geographical reasons) very different from those of elsewhere in the country. 
In a press conference during which reporters were trying to analyse his political personality, Huey Long said, "...say that I am "sui generus", and let it go at that."
American anthropology
Attention to symbols, the meaning of which depended almost entirely on their historical and social context, appealed to many Boasians. Leslie White asked of cultural things, "What sort of objects are they? Are they physical objects? Mental objects? Both? Metaphors? Symbols? Reifications?" In "Science of Culture" (1949), he concluded that they are objects ""sui generis""; that is, of their own kind. In trying to define that kind, he hit upon a previously unrealized aspect of symbolization, which he called "the symbolate"—an object created by the act of symbolization. He thus defined culture as "symbolates understood in an extra-somatic context."