This qualifier directs DFU to delete the complete contents of the
    specified directory, followed by a delete of the directory file
    itself. See also the /TREE qualifier. The parameter must specify
    a full directory file name. Wildcards may be used. Examples :

    DFU> DELETE mydisk:[000000]gone.dir/DIRECTORY

    gone.dir will be deleted with its contents.

    DFU> DELETE/DIRECTORY mydisk:[maindir.subdir]removethis.dir

    removethis.dir will be deleted with its contents.