cable on proportioning valve

So im new to subaru.

I have an 85 brat and I see there is supposed to be some sort of cable on the proportioning valve for the brakes.

Can anyone tell me where it should go and what it does exactly?

I photo would be GREAT

Phizinza did a similar swap, have a look on www.offroadingsubarus.com

He also helped me on my 1,59:1 low range