Sui generis
Sui generis (; ) is a Latin phrase that means "of its (his, her, their) own kind; in a class by itself; unique."
History of Sussex
Borough-English was the custom that lands should descend to the youngest son or daughter, or, in default of issue, to the youngest brother of the deceased. The name originated from a case in Nottingham in 1327 when the English borough, or part of the town, held to ultimogeniture, the French (Norman) part to primogeniture. In Sussex, inheritance by Borough-English, could still be found on 134 manors after 1750.