Presumably the second zone is a simple IR remote, which means that if you are running it from another room you would need to have an IR receiver and some wire to get signals from that other room back to the equipment rack. There looks to be at least one rear IR input, so you wouldn't necessarily even need to stick an emitter on the 990's face to deliver the signal.

They may be shaking the bugs out of the manual - it it's like project specifications, it's one of the last things that gets done.