The documentation refers to 'the KeyNavigation attached property', 'the Keys attached property', 'the LayoutMirroring attached property'.

• http://doc.qt.io/qt-5/qml-qtquick-keys.html
• http://doc.qt.io/qt-5/qml-qtquick-layoutmirroring.html
• http://doc.qt.io/qt-5/qml-qtquick-keynavigation.html

However, none of these are attached properties. Keys, KeyNavigation and LayoutMirroring are all 'attaching types':

http://doc.qt.io/qt-5/qtqml-syntax-objectattributes.html#attached-properties-and-attached-signal-handlers

Keys.enabled is an attached property, Keys.backtabPressed is an attached signal, Keys is an attaching type.

Similarly, ListView is an attaching type. ListView is not an attached property. ListView.isCurrentItem is an attached property.