Tektro z-link alignment lines...
 

I notice that the straddle/z-link wire on my Tektros has a line on the button to use for brake alignment.

Just wondering:

1. What are these things actually for? Seem like they don't matter. It's already easy to align brakes....
2. Are these for brake alignment when brakes are engaged, or for when they're "open"?
3. Does it matter if you're off a bit? Mine are definitely off, but brakes work fine. I don't see how you can align these every time w/all the different variables in brake setups out there (pad thickness, boss spacing, etc.)

I'm guessing these are leftover tech from the older style, smooth post cantis. In that case, I can see using them to initially align your brakes and then sliding your pads to the right position. But I could be totally wrong here.