This page provides the Higgins definition of an r-card ("relationship card").
An r-card is a superset of the functionality of an m-card as defined by the MS ISIP specification. The differences are:
- Both r-cards and m-cards include a pointer to the issuer's STS for obtaining a security token.
- An r-card includes a second pointer: a Higgins Relation to the Digital Subject to which the r-card applies. This relation is provisioned by the r-card issuer, and points to the Digital Subject in the Context designated by the issuer.
- An r-card capable Selector receiving this r-card can resolve the ContextId of the Relation (see that page for details) to discover the data sharing protocol by which the selector can communicate with the designated context. Any protocol can be used; XDI is one protocol designed for this purpose.
R-Card Extension to the M-Card Schema
The only extension necessary is a single element, Relation, from the Higgins namespace. Following are examples of such an element:
RelationXRI (using XRI 2.0 syntax):