in my opinion, there is no gap in the Constitution. In Art. 2.1.1 it says:
"Further, each Circle may control its own functions and activities, as if a Domain of the Circle, for the purpose of defining Policies that limit the Circle’s Roles."
Therefore a policy can limit all functions and activities of the Roles within the Circle. This in combination with:
"You may also define “Policies” for your Domains, which are either grants of authority that allow others to control or cause a material impact within a Domain, or limits on how others may do so when otherwise authorized."
gives a pretty good definition of what a policy is.