[jasonhong]

Yes, in a later version of the book, Norman differentiates between signifiers (which we might now call perceived affordances) and affordances. However, the HCI field and UX field has by and large not adopted signifier as part of its vocabulary, and most people use affordance to mean the perceived relationship rather than Norman's original definition.

It's also worth pointing about that the original definition of affordances, by Gibson, is about animals and their relationship to their environment, which can be quite broad in its totality.