This rule detects public types that does not belong to the unnamed module, whose package is not declared to be exported and are only used inside its own package, in order to reduce its visibility to package-private (**Scenario 1**). Moreover, this rule also detects package-private and not exported public types that are only used by one compilation unit inside its package, in order to reduce its visibility to private, making them static inner classes (**Scenario 2**). Types that are not used by any other type in the project are not considered.