/sys$common/syshlp/helplib.hlb SET, FILE, Qualifiers, /ERASE_ON_DELETE  *Conan The Librarian (sorry for the slow response - running on an old VAX)

    Specifies that the specified files are erased from the disk (not
    just written over) when the DELETE or PURGE command is issued for
    the files. See the DELETE/ERASE command for more information.