First off, apologies to the purists because the plural form is cappuccini. And no self-respecting Italian would dream of drinking a cappuccino after 11 in the morning.
After a meal? "Ma perche?" – "but why?" an Italian might say – a rich and heavy, milky drink after food? Inconceivable. "But why not?" you might ask. It's just not done, end of story.
I once heard a pair of unfortunate young women tourists ask for "a cappuccino coffee" in mid-afternoon at a bar in Rome. The sigh of exasperation that accompanied the telling-off from the barista was louder than the hiss of his espresso machine.
There are several inviolable protocols that will brand you as a barbarian in Italy. Allowing your kids to run around barefoot out of doors, except at the beach. Sitting in front of an icy blast coming from an airconditioner, which will cause irreparable damage to your kidneys/lungs/heart, proof of a neglectful upbringing. Asking for parmesan with a seafood pasta dish.
As for requesting grated chocolate on top of a cappuccino, just don't.