I think an electronic keypad works better as a example.
You get to a door, and there is a postit note on the door saying "Keycode is 2424".
You know your job is in the building. Your keycard let you into the room with the door. Therefore, if this door lead to a "high-security" area, surely they wouldn't put a postit note there? Maybe, as the bug exterminator, or maintenance person, it is expected that I should be able to enter that room?