qtbase/src/plugins/platforms/windows/qwindowsfontengine.cpp and qtbase/src/plugins/platforms/windows/qwindowsfontenginedirectwrite.cpp contain several classes documented like this:

/*!
    \class QWindowsFontEngine
    \brief Standard Windows font engine.
    \ingroup qt-lighthouse-win

    Will probably be superseded by a common Free Type font engine in Qt 5.X.
*/

As the replacement doesn't seem to have happened yet, this documentaiton should be updated.