Packaging rules are sequenced and applied from the lowest priority to the highest priority. A rule's priority is determined by where it is defined. Rules defined by the packaging instruction method packagingRulesFor: have the highest priority. The priority of rules defined by applications is determined by the application prerequisite chain, with dependent applications having the higher priority. Within a method that defines rules (a rule store), the relative order of the rules determines priority, from lowest to highest.

The rule store methods that application might define have the following relative priority, shown from lowest to highest:

If a higher priority rule conflicts with a lower priority rule, the higher priority rule takes precedence. For example, if Kernel specifies to exclude the class Bag, but CommonWidgets specifies to include the class Bag, the class Bag will be included.

When you select a component in the Image Contents Browser, any rules referring to that component are displayed. The rules are qualified as applied, overridden by higher priority rules, disallowed by the rule policy, or not applied due to an unsatisfied condition. If a rule becomes overridden, the higher priority rule that overrode it is shown.