what is a "federation issue" in a bug reporting system

There are different categories in bug tracking systems. One of these categories is "federation". What does it really mean?

My guess would be this would refer to tasks that are required to "federate" (bring together) other systems or tools. So maybe things like SSO (single sign-on) or an enterprise wide "portal" that aggregates other tools.

I think it is to do with user authentication etc... See: http://en.wikipedia.org/wiki/Federated_identity