Tailored solutions for various affordances

A weird keyhole which needs more information about what sense to turn the key ("ouvrir" in french means "open"):complex affordance requires simple solution

And an elegant solution to the "elevator button issue": how to know which of the "up" and "down" button to choose: what's the underlying rationale? what's the referential? the elevator that you want to come down? or yourself who wants to go up? A basic caption with "to go up" near the button is a good fix. Elevator issues