When I first stepped on a GNER train I found it all terribly confusing. There seems to be a special carriage for everything. And then when you finally do find a carriage that isn’t special in some way, all the seats are reserved! I think coach D is the quiet coach where you’re not allowed personal stereos or mobile phones and somebody goes “shhh!” if you cough. Coach F is for people who wear hats, while coach B which is the smoking carriage. Although they may as well call it the “addicts” carriage because I recall half of the passengers were drinking aswell. It hits you as soon as you enter. You can’t miss it really. The amount of smoke in there is just ridiculous and seeing anything becomes an achievement. Going into the smoking carriage, even just to pass through it, is a mistake.
Recently when I was on a nice normal First ScotRail train the guard dude made an announcement (his emphasis): “Passengers are reminded that smoking in the toilet is prohibited,” before somebody came out of the toilet looking pretty sheepish.