Don't what?

@Jen: Haha!

@Suby: I couldn't either; don't worry! When I did find out, I was the one going, "oohhhhhhhhhhhoook!"

@Reza: Je suis désolé, mon français est pauvre ! J'ai étudié un petit dans highschool mais cela l'est ! Je disais juste comment sale mon esprit était quand je lis ceci ! Je sais qu'il signifie maintenant ! Aujourd'hui un bruit sec est-il interroge : vous pouvez me dire ce que « ne Voûte pas » les moyens sur le chemin de fer ?

@Stunner: LoL Well I guess as the end of my day draws in, I will go ahead and explain.

"Do No Hump" is telling other trains to not push other cars at a station or yard. When a couple of trains would get backed up at a station or yard, sometimes they would help push the next train forward. That is what is called "humping." It works great when people aren't on board but when it was a diner car or a car meant for travellers, "Do Not Hump" would let other trains know other people are on board and they shouldn't bump the preceeding train. That way people weren't getting knocked about the car while trying to get situated.

Now all together, let's go, "OOooohhhh! Ooookay! I get it!"