Trenitalia regional trains DO sell out

I'm no expert, but something feels off here. I did a little online research and think that perhaps the one sold out was the IC train, which does run this route?

It’s marked as Regionale.

This is only the case for a few regional trains, and certainly not that common. You see that on www.trenitalia.com when you look up the prices.

If you see "2 Classe" then you can always buy tickets. If you see "2 Classe Prenotazione" then indeed they only sell tickets for that train up to the number of seats.

Looking at Palermo - Cefalu I see that some trains have "prenotazione" marked, but others do not. I wonder what would happen if you bought a ticket for that other train, and then boarded a "sold out" train anyway. That is the trick you do in France for example.

You know, that’s a good idea. I should have done that. I highly doubt the train staff are checking to see if every person has a ticket. Oh well, I’m always on the 9:31 am train.

For several years now (in fact, since the COVID-19 pandemic), Trenitalia has been enforcing a maximum capacity per train on certain specific busy routes to prevent extreme overcrowding. If a train (especially the early morning train, which is popular with commuters and day-trippers) runs with shorter train sets, the sales limit is quickly reached. Both the ticket machines at the station and the app will then refuse to sell any more tickets.

The most practical option is to download the Trenitalia app. There, you can also see how many tickets are still available for regional trains.

What I still wonder is what would happen if I were to buy a traditional undated regional ticket (these still exist) and then just stamp it and get on the supposed "sold out" train. That is what people do in France on those TER lines where SNCF has been doing something similar.

In the past when buying tickets from a ticket vending machine you did not even select a train from a schedule. You just entered your destination. Same when purchasing a ticket at the ticket window.

Its only recently with the change to having people select a train first that railways actually have an idea which train a customer plans to take. And they seem to abuse that a bit...

IC trains aren't regional trains, and they are clearly marked as such. I remember at the Cinque Terre how they even made announcements when the IC called at Monterosso that people with regional tickets and Cinque Terre Cards could not use that train.