[chikko]

here's some more:

all - all tracks
best - only tracks with 3 stars and up
rated - all rated tracks
notrated - all tracks which have not been rated yet
mostplayed - i think it's understood..
never - never played before
heb - only tracks in Hebrew (can be altered into any other language
eng - only english tracks (there could be a problem with languages which has same letters as in english - can be fixed by using the "doesnotcontain" rule)