On some important sacrificial days. You will see some descendants erect monuments to the graves of their ancestors. One is to show solemnity, and the other is to show filial piety. Therefore, erecting a monument has become a common thing. There is an old saying in the countryside that the stone tablet is crooked, which is easy to understand. Refers to the stone tablet standing in front of the grave, if it is crooked. Then it means that when the family is unhappy, it will be unhappy, and there will be fewer people who will reproduce.
If the memorial tablet is tilted, you can just straighten it when you visit Tomb-Sweeping Day, and it is best to straighten it when you visit the grave in Tomb-Sweeping Day that day.