That seems kind of baroque, but it doesn't have to be.
Returning to our scenario above:
- Dr. Drang keeps a list of blogs he ‘follows’ or endorses, and so do I. And it so happens that Dr. Drang's blog is on my list.
- Anyone who is on Dr. Drang’s list can now send me a web mention, even if I’ve never heard of them before.
The beauty of this approach is that it offers all the benefits of whitelisting without whitelisting’s super-rigid resistance to newcomers.