Concerning regional trains, the Trenitalia website says: "Your online ticket is already validated and allows you to travel on your pre-chosen train or on others - along the same route - in the four hours after the time originally selected at the time of purchase, except for exceptions foreseen with specific regional tariffs." (I think this applies whether the ticket was purchased at the station or online.) Does anyone know what "except for exceptions foreseen with specific regional tariffs" means? Does it mean that you will not be allowed to use certain trains if you miss your original train? Or perhaps you have to pay a tariff to take a different train? If so, would you pay the tariff on board? I am chatting with Trenitalia trying to find out, but after I was greeted I was told to wait for another operator to continue the conversation and haven't heard anything in two hours.
Also, I read elsewhere some people were given only a three hour window...any experience with that?
Finally, is the Cinque Terre Express considered a regional train? So if you miss it, can you take another Cinque Terre Express within the four hours? Would you also have the option of a using a regional train in the four hour window if you bought a Cinque Terre Express ticket but missed it?
I really appreciate everyone's help.