special act
Noun
Meaning
a legislative act that applies only to a particular person or particular district
Source: WordNetHypernyms
Examples
By special act of Congress, he was commissioned a 1st Lieutenant in the Marine Corps on 4 March 1914.
However parliamentary delays meant it was 4 March 1756 before a special act of parliament created four battalions of 1,000 men each to include foreigners for service in the Americas.
Texas was added later by a special act passed in 1906.