G11 -- Immediately White Balance Rest
You probably already know this but it was news to me.
Originally, I wanted to set the shortcut button to give me quick access to manually setting the the white balance, so I set it to WB. Then the shortcut button would give me the white balance menu and with a couple more steps I could manually set the white balance.
I did not realize that if you set the shortcut button to custom white balance 1 or 2, the shortcut button operates much differently.
If you set the shortcut button to one of the custom white balance settings, when you push it, it will immediately make a white balance exposure and reset that custom balance to the new exposure. In essence all you need to do is point the camera to somthing white and hit the short cut button and it's done -- very fast, one step.
It's in the manual on page 156.