The article is a good start. I can add what's helpful in my experience: Core RBAC includes users, assignments, roles, permissions, operations, objects, and sessions.

For a system that implements RBAC, the objects can represent information containers e.g. files/directories within an operating system, locks on columns/rows/tables within a database management system, tags on resources within an application, exhaustible system resources such as storage or CPU cycles, etc.

The ANSI RBAC spec is here: http://www.list.gmu.edu/journals/tissec/ANSI+INCITS+359-2004...