Major Description
Today once a document has a value in a certain DV field this values
can only be changed but not removed. While resetting / removing a value
from a field is certainly a corner case it can be used to undelete a
soft-deleted document unless it's merged away.
This allows to rollback changes without rolling back to another commitpoint
or trashing all uncommitted changes. In certain cenarios it can be used to
"repair" history of documents in distributed systems.