(ds9) Backend documenatation provides little and incorrect details

Pages like
http://doc.trolltech.com/4.5/phonon-ds9-volumeeffect.html list the function names in that class but do not refer correctly to the Phonon documentation of the interfaces it implements. Idealy this documentation should be changed to provide a brief explaination of the class and refer to the Phonon documenation for the API's it implements