Arctic Fox 27T solar ready, what does this mean exactly?

Northwood emailed me asking for mailing address so expecting them to send me something...

While chasing a different problem (water heater stopped working on gas, posted another thread), I was fixing the ground near the battery boxes and noticed the other end of solar wires near the battery boxes. It is 8 gauge (red and white) pair that goes from back overhead cabinet to the front near the battery box. It will be interesting to see what Northwood sends me.