This annotation can be applied to a package, class or method to indicate that the method parameters in that element are nullable by default unless there is:

• An explicit nullness annotation
• The method overrides a method in a superclass (in which case the annotation of the corresponding parameter in the superclass applies)
• There is a default parameter annotation applied to a more tightly nested element.

This annotation implies the same "nullness" as no annotation. However, it is different than having no annotation, as it is inherited and it can override a ParametersAreNonnullByDefault annotation at an outer scope.