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."
Pensions in the United Kingdom
These are type "sui generis" as they either reward a career in domestic politics or are awarded in the colonial context not on grounds of justice, contract or socio-economic merits, but as a political decision, in order to take a politically significant person (often deemed a potential political danger) out of the picture by paying him or her off, regardless of seniority.