In an analogy to Pingbacks, Mike Bijon (aka Moogle1) proposes to create a higher-level specification by which bloggers can express trust in other bloggers. Actually, I think it is about people with a URL expressing trust in each other, closely related to URL-based identity. Certainly he says that it would require an identity system and I suspect he’s thinking about URL-based identity in that context.

I very much like the idea, once the somewhat difficult details are filled in. He says:

I should be able to maintain a skill profile for my trustbacks to better show the credibility of my skills and to avoid the “list of my friends” that seems to be the core of most current social networks …

As I’ve said repeatedly before, I might trust somebody to write correct code but not trust them to babysit my kids; and vice versa. There are many examples like that. So unless "trust" is qualified with "about what", it indeed turns into a glorified list of "all the people I know" very quickly.

Unfortunately, the "about what" seems to require a full, life-scale ontology in the general case, and I haven’t seen a proposal yet to simplify that dramatically without limiting usefulness too much — or accidentially expressing the wrong "about what" to consumers of trust information.