Never, Ever Ever Ever EVER EVER EVER Turn This Switch OFF!!! EVER EVER EVER!!!
To me this felt like overkill to me. Maybe instead of wasting the time to write this note card out and plaster it to the stereos you could have taken 5 mins and trained your entire staff on what that little switch does... why it's a bad thing to have it in the off position... and what the results of flipping the switch would be. Wouldn't that just make sense!?