Yamaha RX-V661 please explain zone2/b/front?

The manual is putting my brain in circles.

I get the basic idea, zone2 is another channel you can use independently. Not sure what zone b is and speakers B does not act right?

Most stereos have a A/B speak assignment. So does the v661 but it has no function? If I set a,b,a+b, or none all speakers still work?

I have speaker set to zone2 in another room, and my speakers front B go out back. currently there is source 1 on my main receiver. I set the zone2/front to font in the menus and out back I here source 2 out back. So I did something right. Though I can not adjust that volume. Now if I set zone2 in the menus I get my second room playing source 2 and I can set the volume.

So I guess what I'd like to know is how can I change the volume of the front B speakers. Also why does the A/B not do anything?

Sort of expected that, but its not playing what the receiver is. I obviously have a mess here...
( ok here is the deal )
My out door comes from zone2 RCA
My second room comes from speaker wiring zoneB/front

Now when I adjust the volume for zone2 the second room changes if set to zoneB but the volume for the zone2 ( RCA ) does not change. Can it?

Thinking it over, I dont see why RCA out would change volume. So I guess that answered that.

I have no idea what Yamaha was thinking here. But here is what I here.

Zone 2 is playing source2
main is playing source 1
Zone B is playing source2

This is accruing all at the same time. I dont even know what to think. All of this coudl have been a lot more clearer in my opinion.