ms-a102 occupancy switch mysterious green/yellow wire

There is a unusual green/yellow color wire coming out of the MS-A102 switch. The wiring diagram says to connect this wire to the ground.

I'm guessing the green/yellow is basically the neutral wire for the device.

If a neutral wire is available in the switch box, would it be better to connect the green/yellow wire to neutral?

Not sure what it is for, but I installed some of these in a bathroom without using the green/yellow. Lights would NOT turn off (and it's in the troubleshooting section). Attache the green/yellow to the ground and you'll be good.