Library /sys$common/syshlp/dbg$help.hlb DEBUG, EDIT, Qualifiers, /EXIT  *Conan The Librarian (sorry for the slow response - running on an old VAX)

       /EXIT
       /NOEXIT (default)

    Controls whether you end the debugging session prior to starting
    the editor. If you specify /EXIT, the debugging session is
    terminated and the editor is then started. If you specify
    /NOEXIT, the editing session is started and you return to your
    debugging session after terminating the editing session.