Public Class MyTestClass

  ' Can be used as MyTestClass.PublicInnerClass by anyone
  Public Class PublicInnerClass
    '...
  End Class

  ' Can only be used by MyTestClass or derivatives
  Protected Class ProtectedInnerClass
    '...
  End Class

  ' Can only be used by MyTestClass
  Private Class PrivateInnerClass
    '...
  End Class

End Class