QDir::Filter documentation is lacking the enum PermissionMask

QDir::Filter enum should state that QDir::PermissionMask has to be used with QDir::Readable in http://doc.qt.nokia.com/latest/qdir.html#Filter-enum. The documentation is lacking the QDir::PermissionMask entirely.

Setting the following filter to QFileSystemModel doesn't show any files of folders
modelIndex->setFilter(QDir::AllDirs | QDir::Files | QDir::NoDotAndDotDot | QDir::Readable);
but adding QDir::PermissionMask shows the desired files
modelIndex->setFilter(QDir::AllDirs | QDir::Files | QDir::NoDotAndDotDot | QDir::Readable | QDir::PermissionMask);