This integer sets the routing preference value applied to routes that match this import policy, but the description notes it only takes effect when csImpPolAction is set to permit; -1 means the preference has not been set. An admin uses it to make routes coming through this policy more or less preferred relative to routes from other sources. For example, setting csImpPolPreference to 50 on a policy for a secondary provider peer makes those routes less attractive than a primary peer's routes carrying a lower preference value.