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."
Prince du sang
A prince du sang (, Prince of the Blood) is a person legitimately descended in dynastic line from any of a realm's hereditary monarchs. Historically, the term has been used to refer to men and women descended in the male line from a sovereign, although as absolute primogeniture has become more common in monarchies, those with succession rights through female descent are more likely than in the past to be accorded the princely title (e.g., Belgian Royal Family).