HAI RC2000 Custom Message

[Acropolis]

I just upgraded from an older Omnistat RC80 to the Omnistat RC2000 (moving the RC80 to the basement). I noticed in the system setup of the RC2000 you can select which messages are displayed. One of the options is to display "custom message". I have a couple of questions about this feature.

1. How do I send a message to the RC2000? I have sent messages to my consoles before, but never a thermostat.
2. Can you send a message to only the thermostat, or do custom messages go to all devices (consoles and thermostats)?

Thanks in advance for the help.

Nick