Gives a generic "paste this code into your page" and it'll search pages you link to. Which is brilliantly simple.
I tried on a new test page with one link and it failed 404. I tried on an established page, using exactly the same included content and it worked immediately.
Am I missing something, as I'd dearly like to just drop this on pages as needed, but the default error if the page isn't indexed yet is a messy 404 error which would send the users we deal with in web page creation running to the hills.