The items in a collection in this specification are unordered and may contain duplicates.

The effective policy, for a given policy subject, is the combination of relevant policies. The relevant policies are those attached to policy scopes that contain the policy subject.

The element policy is the policy attached to the policy subjects associated with the element information item that contains it.

An ignorable policy assertion is an assertion that may be ignored for purposes of determining the compatibility of alternatives in policy intersection in a lax mode (as defined in 4.5 Policy Intersection).

A merge consists of serializing each policy as a policy expression, replacing their wsp:Policy element with a wsp:All element, and placing each as children of a wrapper wsp:Policy element.

A policy is a potentially empty collection of policy alternatives.

A policy alternative is a potentially empty collection of policy assertions.

A policy assertion represents a requirement, a capability, or other property of a behavior.

A policy attachment is a mechanism for associating policy with one or more policy scopes.

A policy expression is an XML Infoset representation of a policy, either in a normal form or in an equivalent compact form.

A policy scope is a collection of policy subjects to which a policy may apply.

A policy subject is an entity (e.g., an endpoint, message, resource, operation) with which a policy can be associated.