Shift+Click? Heros

So i keep hearing you can disable certain skills on the heros skillbar.

Now since ive rebinded all my keys, what is the menu command i need to change/use?

What was shift originally binded to is what i am asking.

Also how will i know its been disabled? Will it be grayed out or have a red x through it?

Yes a click puts a check mark telling the hero to use that skill ASAP, if disabled it gets an X.

I don't think shift was a bound key, it was...shift.