LOL! You mean like the old flaming red stickers declaring “GUN INSIDE”?
Reminds me of the Time I flew to Texas to do some hunting.
When I checked in they made me open my Rifle case to prove to them it was unloaded and had no Cartridges in the case.
The People in the other lines got real big eyes and were locked on the Rifle. Yeah People, you put Rifles in Rifle Cases...
I laughed, Citiots!
No. Continental/United didn’t mark the bags at all when I traveled with a W. Maybe they do now?