Walking into nursing homes in Tokyo, you will notice something interesting.  Hanging on the door of each room，next to the room number and the resident’s name, there is a small box, each containing different decorations, for example, a cloth doll, an origami paper crane, or a Japanese fan.

Because of poor memory caused by aging, the elderly residents often entered the wrong rooms by mistake.  To help them locate their rooms more easily, this special door box was designed to contain each resident’s favorite decorative item to help them identify their rooms.

Source：
http://travel.huanqiu.com/culture/2011-04/1637711.html