Check Out

On the wall in one of my oncologist's exam rooms, near the door, there is a sign that says, "Check Out."  




This is not the real sign


It may have been there all these years and I never noticed. Maybe I've never been in that exam room before. I'm not sure what it is telling me - is it reminding me to check out with the doctor's assistant before I leave?  Is it a reminder for the physician?