The DELETE FIELD command deletes a field element from a
    repository.

    If a field element is controlled, CDO freezes previous versions
    and allows you to delete only the highest visible version. If a
    field element is uncontrolled, CDO deletes the highest version
    unless you specify another version number.

    You cannot delete a field that is a child. Delete the parent
    first, or include the /DESCENDANTS qualifier to delete parents
    and children at the same time.