u/David-Jiang

I know paper tickets are few and far between now, but the systems that still have them or had them until recently (like the Las Vegas Monorail and RTD and BART) all have this little hole on the top. My first thought is a keychain hole, but that doesn’t make sense because these tickets often need to be inserted through the fare gate in their entirety. Do you guys know what this little hole is for? Have you ever used it for anything?