On the REST discussion group, Jeff Bone is digging into the foundations of the Web, searching for the backbone to its architecture.
He's brought up a key point about addressability on the Web (don't know how it relates to REST, but that's for another day).
Some resources are retrievable, but aren't listed anywhere. So how do you let clients know about these unlisted numbers?
He suggests - with a lot of backup material - that delivering a description of the naming structure lets clients access truly huge amounts of information easily. He calls this 'generative naming'.
I think he is right.