Sometimes it's the government determining it
>>> ...friend determines which holes in the earth can be recycled ...
http://www.scmp.com/magazines/post-magazine/short-reads/article/2019657/changing-face-hong-kong-carved-its-gravestones
[...]
Times have changed. Hong Kong’s modern gravestones are not expected to last “forever”; in fact, their average lifespan is about seven years in public cemeteries, which is the length of time that elapses before the grave is exhumed and the plot reused for another occupant.
[...]
http://www.scmp.com/magazines/post-magazine/short-reads/article/2019657/changing-face-hong-kong-carved-its-gravestones
[...]
Times have changed. Hong Kong’s modern gravestones are not expected to last “forever”; in fact, their average lifespan is about seven years in public cemeteries, which is the length of time that elapses before the grave is exhumed and the plot reused for another occupant.
[...]