Sui generis
Sui generis (; ) is a Latin phrase that means "of its (his, her, their) own kind; in a class by itself; unique."
R v Guerin
Guerin v The Queen [1984] 2 S.C.R. 335 was a landmark Supreme Court of Canada decision on Aboriginal rights where the Court first stated that the government has a fiduciary duty towards the First Nations of Canada and established Aboriginal title to be a "sui generis" right.