@plactagonic @tml In Italy, if you bought a combined ticket, IIRC it's considered validated from the time of the regional train you were supposed to take and may expire after a certain number of hours.
The train number might be significant to some. Say you're going Milano-Como and you miss train 25076; you may guess that train 25080 is the next equivalent, while you might doubt whether the next train to Chiasso is the same. Or they could just say it's line S11! Naming things is famously easy.;)