This inspection detects plugin components and actions that are not (yet) registered in a plugin.xml descriptor and offers a QuickFix to register the component. This eases developing new components when making use of the "Create Class" intention and helps to keep track of potentially obsolete components.

There's an option to turn off the check for Actions as they may be intentionally created and registered dynamically. Note that the inspection can also be suppressed on a per-class level, so it normally shouldn't be necessary to switch off the inspection completely. Especially because the inspection ignores abstract classes and by default non-public classes as well.