A circle can make policy just for itself, both on process and on their work. For example, a circle might determine how they run their own meetings, or they might make a policy that only affects their own workflow. A circle can also, in their domain, make policy that is in effect organization-wide. For example, depending on how the domains are defined, a membership circle can have authority to make membership decisions for all members of the organization, not only the circle.
For more information, check out our handbook Many Voices One Song chapter 3