What does it mean to pull a grave by clan in geomantic omen?

The customs and habits in some areas are also due to geomantic omen. The ancestral graves have been used for a long time, and the feng shui fortune has declined, so it is impossible to build and replenish them. It is necessary to re-select the land of geomantic omen and bury the golden bones. We call it pulling the grave. Some ethnic groups there also have this burial custom. After several years of burial, they reopened the grave and moved their bones to another place for burial.