Power brake linkage notch

[themechanic]

What's the deal with the power brake linkage notch? What's it's purpose? Why does the FSM show the notch facing the booster?

 

[gkent]

My guess would be clearance for something.

 

[themechanic]

Only thing in the path is the rubber dust seal on the back of the booster but it doesn't appear to go far enough to hit it.

 

[steve340]

It may be away of identifying the orientation of the parts during manufacturing and assembly.
I used to work in a machine shop making drilling and welding jigs and we had to make them so the guys running the machines fitted the parts the right way around.