WHITE BANNER ACROSS DOOR AS SIGN OF WHITE OCCASION

During weddings, grand openings and grand birthdays, the Chinese will hang red banners at the door entrance to their homes as a sign that there is a red occasion.  When a red banner is hung, then it is a sign of a white occasion where there is a death in the house.
In the above picture, you can see the undertakers putting up the white banner at the entrance to show that there was a white occasion in the household.