The LGI$ICR_IDENTIFY callout routine is invoked for all types
    of login procedures. If the site uses the standard OpenVMS
    DECwindows dialogue, the identification routine may be called
    more than once for accounts with two passwords.

    If you plan to replace the standard OpenVMS identification
    processing, consider the following:

    o  For logins from character-cell terminals, obtain the user name
       using one of the following:

       -  A dialogue with the user. The site can access OpenVMS
          user name processing to obtain the standard prompt or
          a specialized prompt by invoking the LGI$ICB_USERPROMPT
          callback routine. Alternatively, the site may invoke the
          LGI$ICB_GET_INPUT callback routine to communicate with the
          user.

       -  Site-specific equipment, for example, a card reader or some
          other authentication device.

       -  Autologins. The site may do the identification portion of
          the standard OpenVMS autologin by invoking the LGI$ICB_
          AUTOLOGIN callback routine.

    o  For logins from the DECwindows Session Manager, LOGINOUT
       invokes the callout module's LGI$ICR_IDENTIFY callout routine
       after obtaining the user name and putting it in LGI$A_ICR_
       USERNAME. The LGI$ICR_IDENTIFY callout routine can provide any
       additional checking of the user name that may be required.

    o  For batch jobs, network jobs, logged-in DECterm sessions, and
       subprocesses, the site may use the LGI$ICR_IDENTIFY routine to
       verify information without a user dialogue.

    Calls to LGI$ICR_IDENTIFY are always followed by validation of
    the presence of the user name in the system authorization file,
    unless the routine is invoked for a subprocess.