Fielding writes in his famous dissertation (p.89) that although the entities referenced by a resource may change, the resource's semantic meaning must not.
So a resource
prot://bookstore.com/new-books-this-week is OK, because although it will always show different books every week, the semantic meaning does not change.
What I can't come up with, is a good example of how a URI has to be designed so that it semantic meaning can change. So I am looking for a counterexample. Of course in the above URI I could suddenly start returning new books from this month or even cars. But this is trivial.
What would be a demonstrative (often used?) URI pattern describing a resource that violates the "do not change the semantic" rule?