When you arrive at your new home, you should hang a red lantern on the door to show that you are separated from this home.

Later, this tradition was inherited by the descendants of the family. However, when they come to a new place to settle down, future generations will hang a red lantern at their doorstep. The implication is that they want to find someone who comes out of their family. Second, they remind their descendants not to forget that they have always been people who came out of this family.