An administrator may need to delegate one realm's policy definitions and decisions to another realm. (Alternatively, policy decisions for a resource can be delegated to other policy products.) A referral policy controls this policy delegation for both policy creation and evaluation. It consists of one or more rules and one or more referrals.
A rule defines the resource whose policy definition and evaluation is being referred.
The referral defines the organization to which the policy evaluation is being referred. By default, there are two types of referrals: peer realm and sub realm. They delegate to an realm on the same level and an realm on a sub level, respectively. See Creating Policies for Peer Realms and Sub Realms for more information.
The realm that is referred to can define or evaluate policies only for those resources (or sub-resources) that have been referred to it. This restriction, however, does not apply to the top-level realm.