These tickets are good for all “Nah- und Regionalverkehr,” explicitly excluding ICE, IC, EC (international) and long-distance busses (like the one between Munich and Zürich)
If the train number begins with RE or RB, you’re good, but of course, those are the slow ones that stop in every village along the way.
This is for the benefit of people who live here and are struggling with 2 EUR/liter fuel, not the kind of people who blithely paid 60 EUR to take the ICE. There does not appear to be any residency requirement, but remember, you’re not the target market for this (unless you live here and are struggling with fuel prices…)