Adrian wrote:

I'll bet that if you went to the buffet car on an intercity and asked for a
glass of tap water you'd get one for free.

No, because they don't carry any in a drinkable form. I recall a
notice being displayed quite prominently saying (mainly to parents with
babies) that they couldn't supply tap water because it was not
drinkable, as the buffet cars didn't have the correct infrastructure.

Neil