Whether it is or isn't a genre or subgenre convention, or codifier of same, isn't really the issue. (madgeniusclub.com)
As noted in the materials linked by K - C, some titles of the United States Code are passed in that form «as a title» by Congress, while others were historically assembled editorially by the code codifier's editor from annual «Public Laws», often in a less than stellar effort. (law.stackexchange.com)
This improves the ability for localities to import data from their current codifier. (statedecoded.com)