This message is being displayed by the BULLETIN facility.  This is a non-DEC
facility, so it is not described in the manuals.  Messages can be submitted by
using the BULLETIN command.  System messages, such as this one, are displayed
in full, but can only be entered by privileged users.  Non-system messages can
be entered by anyone, but only their topics will be displayed at login time,
and will be prompted to optionally read them.  (This prompting feature can be
disabled).  All bulletins can be reread at any time unless they are deleted or
expire.  For more information, see the on-line help (via HELP BULLETIN).