Which leaves me confused with GP's suggestion. Every TSA line I've been in already has these signs. Are airports in other countries worse about their signage than TSA?
I also go through the trusted traveler line, and the rules there are _usually_ different (but not always!) and I definitely don't recall seeing any sign specifically addressing the rules for that line at any point. Except maybe one at the start clarifying _who_ can use the line (though on that one I've also had the TSA agents go ahead and explain the rules entirely different than the sign they were standing in front of so...).
If I worked retail and treated customers like the TSA treats passengers, I'd be fired the first day.