HISTORICAL NOTE
(By Another Hand)
IN the opening week of January, 1923, there appeared on the outside of a certain door within a dingy, sunless, and cramped apartment a slip of paper bearing the following typewritten notice:
Nobody may come into this room if the door is shut tight (if it is shut not quite latched it is all right) without knocking. The person in the room if he agrees that one shall come in will say "come in," or something like that and if he does not agree to it he will say "Not yet, please," or something like that. The door may be shut if nobody is in the room but if a person wants to come in, knocks and hears no answer that means that there is no one in the room and he must not go in.
Reason. If the door is shut tight and a person is in the room the shut door means that the person in the room wishes to be left alone.
