Check above the elevator doors.

Probably, but you have to look up. Most people stare straight ahead or at their phones, so they miss the small brass plaques mounted on the wall above the elevator entrance or right next to the door frame. They’re often original building markers—installation date, architect name, historic designation plaque. If the building is older than 50 years and looks like it has any character, there’s a good chance something is hiding in plain sight.

If you don’t see one, check the lobby wall near the entrance, or the edge of the door frame itself. They’re usually small and easy to overlook