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

       /ERASE
       /NOERASE (default)

    When you delete a file, the area in which the file was stored is
    returned to the system for future use. The data that was stored
    in that location still exists in the system until new data is
    written over it. When you specify the /ERASE qualifier, the
    storage location is overwritten with a system specified pattern
    so that the data no longer exists.