1st class pass entitles you to reserve in Business, the 2nd tier on Frecciarossa trains.

Thanks a lot for this quick and full answer

Best regards

Rainer

@Al_G Does business class grant you access to the lounge and priority lane at big stations?

First class Lounges depends on country.

No: Italy, Germany

Yes: UK, Austria, Netherlands

No doubt others can add to that.

For the most part lanes do not exist in stations, definitely no airport style queues and priority nonsense with the exception of Eurostar London - Paris, Brussles, Amsterdam and there the priority is only for Business Premier which pass is not valid for.

Spain is an outlier in having security theatre for high speed train platforms, elsewhere most stations are either barrier free or have quick ticket checks for platforms.

@Al_G For Trenitalia, there is Priority Lane I believe is this correct?

Thanks for the fast answer

I never heard of such a thing. Only with Eurostar this exist for Business premier tickets. 

For all the rest of Europe, you just show up a bit before departure, find your platform and board. Hup, done. Like with 99% of all trains in Europe. No nonsense or secutainment, as it should be. 

Only passengers with reduced mobility requiring some sort of assistance can get priority. 

In big stations like Roma Termin and Milano Centrale there are ticket controls before entering the tracks area. For Executive class ticket holder and Business frequent Travellers can use a “fast track” ticket control gate. In this case you can’t use it with an Interrail Pass. But usually you don’t  have to wait at the ticket control, it is very fast. Some gates have automatic controls, where you scan your Interrail Pass or reservation.