Paul Madsen has done a nicely illustrated post on the taxonomy of i-cards supported by the Higgins project. He makes a great point about how SAML cards (“s-cards”) could fit in, both in terms of third-party cards and self-issued cards. As I posted previously, I’m excited about seeing SAML integrated into the Higgins framework.

My only quibble with Paul’s diagram is that it shows r-cards (relationship cards) as a subset of m-cards (managed cards). If anything, it’s the other way around — an m-card would be a specialization of an r-card. But actually they are disjoint, the same way Paul shows the r-card and p-card circles in the self-issued set.

UPDATE: Paul has fixed this, and the diagrams are fine now.

The subject is actually very deep, as there are some interesting ways in which r-cards can emulate both m-cards and p-cards. But that’s a deeper subject than I have time for in this post — hopefully I’ll get some time over the holidays to go into it more.