[Sylfest]

Thanks @Sylfest Let me know what you find please.

As black_eagle said. The <actor> tag works very well. By clicking one performer (actor) you can view that persons stuff in the library (movies, tv-shows, musicvideos and albums)
If the "Show all performers for music videos" setting is active they all show upp in music video artist-node. Could be useful for bands that change their lineups and also have solo careers. Pink Floyd is a very good example.

Another thing that comes to mind for the .NFO generator in MMH is the <tag> tag.
For example: <tag>atmos</tag> or <tag>DVD</tag>
This would be brilliant to use for custom library nodes to sort out some concerts/music videos in all possible ways.