Instead of plain: Audio Video there could be: Media/Audio Media/Video ... The extra benefit is that applications that deal with both video and audio could be placed simply to Media.
tracked at https://bugs.launchpad.net/rpm/+bug/911023
Apparently wontfix; jbj@ mentioned that Group: was a wrong concept in the first place (it seems to be missing from fedora specs recently either), debian's faceted classification seems to be most suitable as of today.