Thanks, I stand corrected :) That makes me wonder , I have not been able to imagine a usecase for it when it doesn't return a callable, the article doesn't help in that regard either. Got some thinking to do I guess.

the article mention multiple examples, one of being the "registering things" when it returns the same function untouched, just put away the function instance in a list or something to use it later.

Returning a function would be returning a callable object, which is what I was alluding to. The section under "Decorator Toolbox" contains no suggested usecases for returning a non-callable object, will try and think of something.