Thanks, that's great.

I'm new to access control, and "RBAC" seems to be what I am looking for. I was wondering if you could briefly state pros or cons or limitations or recommendations of 3 designs:

1. this one
2. phpGACL (PHP Generic Access Control Lists)
3. radicore (A Role-Based Access Control (RBAC) system for PHP)

#3 has a RBAC wrapped up inside a framework, and there is a licensing issue. So I may not be able to use that one, despite any merits of the logic (although Tony appears to have a sizeable background designing these things so I hate to dismiss it outright).

Whichever one I end up with I plan to port to CodeIgniter.

Thanks for any thoughts you may have.