Wondering if it's absolutely necessary to book advance tix from Rome to Naples. We are going in early June and our tour of Pompeii is later in the day, and we're still deciding on our overall schedule that day.
Also, is tax code necessary on the Trenitalia website? We booked tix to Florence, and it didn't seem to be required. Just put in the basics -- firstname, last name, birthdate and country of birth.