Oops. Research failure. I'm a meticulous planner when it comes to travel, but on our recent trip to the Netherlands, I failed to note one warning and, as a result, suffered a verbal rebuke in no uncertain terms. So, I learned the hard way that there are cars on trains throughout the country where talking is prohibited. Whoever heard of such a thing?
My wife and I were returning to Amsterdam after a day trip to The Hague. We hopped on the first car that appeared to have open seats and settled in for the hour ride. We didn't note the large "S" on the window nor the smaller "silence" beneath it. Riding through the lovely countryside, we began to discuss our dinner options at a normal conversational level. Moments later, the woman sitting in the seat in front of me turned and in crystal-clear English and a loud tone of voice made sure we knew speaking aloud would not be tolerated. Without responding about the irony, we shut up and stayed that way until we were safely on the platform at Amsterdam Centraal Station. Lesson learned.
After-the-fact research located this very helpful site: https://accidentallydutch.com/guides-to-holland/silent-train-carriage