Chart difficulties

[beebe]

So I've been using FoFiX for some time now, and I've been charting songs for some time now as well and I've found that there isn't really a structured system to decide what a song's difficulty should be. It's pretty accurate when it comes to a lot of the newer guitar charts I've seen released, but I find it especially true in drum charts. Drum chart difficulties are very relative right now, and most times I have a really hard time deciding what a song's difficulty should be. It's not really a big issue by any means, but I would really like to see some kind of guide to deciding what an appropriate difficulty would be for a song.