VMS Help CMS, UNRESERVE, Qualifiers, /DELETE[=file-specification]  *Conan The Librarian (sorry for the slow response - running on an old VAX)

    Controls whether all versions of the unreserved file are deleted.
    If you omit /DELETE, the files are not deleted. If you specify
    /DELETE without a file specification, all versions of the
    unreserved files are deleted from your current directory. The
    file specification allows you to specify a different location and
    the name of the file to be deleted.