the role of the door sign: 1. Function and use, such as: each room in the hotel is the same, with the door sign can quickly find the room to stay. It is also convenient for hotel management. 2. Door number, on some doors, there should be another door sign expressing a bit of information. 3. Guide sign: let outsiders quickly understand this public space. 4. Function sign: used to reflect the function of a certain area or room.