Pretty much why I mark my tunes right now. I think keeping this basic would be the best bet. Just a few different values for the mark flag. If someone wants to use them for rating purposes, then that's up to them. The player doesn't need to know about the different mark types.

An easy indicator would be a slight modification to the current one as well... Currently you get "!!" to indicate d marked track. With multiple values it might be nice to see the following instead: "!1" "!2" "!3"

As an extension, if you REALLY wanted more feedback from the player, then it might be nice to assign a name to each mark type. Then you could easily identify your "rating" or other special purpose mark function. Being able to display a list of marked tracks in the plaer software is a natural extension to even the current marking scheme.

Bruno