In Italy, pane is bread, panino is a roll, panini are sandwiches. And in Milan, from what I have observed, the sandwich reigns. There, panini are assembled with fresh diversity on tender rolls, or popped into sandwich grills to create tostas, to satisfy hungry, hurried customers at paninotecas ― sandwich shops. The package often includes piquant nibbles of pickled onions, mushrooms, artichokes, and other vegetables; a few leaves of some sort; and, with considerable regularity, mayonnaise seasoned as Russian (some would call it Thousand Island) dressing.
Good ideas travel. No doubt you've seen panini on a menu or two. I've spotted them from Seattle to Santa Fe. And at a little Italian restaurant tucked away in a Denver shopping center, I came across this highly evolved focaccia version.