It is not the purpose of the docs to list use cases.  Mostly we say what something does or how it is defined.  As Vedran says, how people use it is their own business.

Also, please be careful expanded the docs.  They quickly become a promise.  Per Doc/reference/introduction.rst, "It is dangerous to add too many implementation details to a language reference document --- the implementation may change, and other implementations of the
same language may work differently."