If the standard OpenVMS autologin functionality applies, the
    callback routine returns the user name to the site program using
    the standard argument vector so that the autologin process may
    continue.

    The autologin determination is made before the site prompts for
    the user passwords. The callback routine is applicable only for
    interactive character-cell logins.

                                   NOTE

       Standard OpenVMS policy uses autologin only on directly
       connected or LAT connected character-cell terminals. The
       LGI$ICB_AUTOLOGIN callback routine checks the automatic
       login file (ALF) SYS$SYSTEM:SYSALF.DAT to make the
       determination.

       A DECwindows callout can include a method for doing a
       DECwindows autologin. In that case, the callout routine
       should set the autologin flag to true before returning
       control to LOGINOUT.