Though you can't always trust them. Even the titles of laws are often the opposite of what the law is accomplishing; and that's intended.
Though laws also sometimes come with justifications. Eg
> Article I Section 8 | Clause 8 – Patent and Copyright Clause of the Constitution. [The Congress shall have power] “To promote the progress of science and useful arts, by securing for limited times to authors and inventors the exclusive right to their respective writings and discoveries.”
In my book, "To promote the progress of science and useful arts" sounds like they wanted to explain what that piece of law was supposed to be good for. But whether handing out monopolies actually promotes progress of science and arts is very much a factual question open to factual enquiry.
And so is the question whether this wording really has anything to do with why the legislators come up with that clause.
It's perhaps more well-analysed for the second amendment to the American constitution.
See https://en.wikipedia.org/wiki/Second_Amendment_to_the_United...
The text itself provides some form of justification for reasons, but from history we know that there were different factions involved all with their own different reasons, and what's written in the law is a compromise. A compromise with rather idiosyncratic phrasing.
Without this clause there would essentially be no restriction on Congress’s ability to establish monopolies.
Though it seems like in practice sufficient motivation is enough to wring extra powers out of the given text. See eg copyright for movies or audio recordings.
Or the monopoly of USPS. (It's a different clause that motivates it, but that clause doesn't prescribe that a government department is called for, nor that it has to be given a monopoly.)
In Canada the legislation is often referred to via its bill number (for a given session/sitting of Parliament):
* https://en.wikipedia.org/wiki/Bills_C-1_and_S-1
But the laws are also organized into Acts, which are sometimes introduced whole-cloth, but more often are amended by bills:
* https://en.wikipedia.org/wiki/Food_and_Drugs_Act
* https://en.wikipedia.org/wiki/Telecommunications_Act_(Canada...
* https://en.wikipedia.org/wiki/Canada_Evidence_Act
* https://en.wikipedia.org/wiki/List_of_Acts_of_Parliament_of_...
This is fairly common in British-derived systems:
* https://en.wikipedia.org/wiki/Category:Statutory_law_by_legi...