What do the lights mean on my home digital base unit?

What do the lights mean on my home digital base unit?

Power Button

Back-lit green indicates the unit is on. Press to hear the status, hold to turn off, press to turn on.

Flashes Orange: Mains power is disconnected. A voice message will notify you.

Solid Red: Battery is no longer functioning or missing.

Flashes Red: Battery is low.

No Light: The unit is turned off.