I stumbled upon this at Planet Battlefield today and it sounds interesting for those running an unranked BF2 server. According to their website, “Alternative Battlefield Ranking is a collection of scripts, which provide the same functionality as the original official battlefield 2 ranks, without having to pay for a ranked server.”
EA/DICE has recently given permission for this effort to go forward regarding Battlefield 2 and Related Products, and it will offer support for general unranked servers as well as those running mods similar to that seen from BFTracks and BFStats in the Battlefield 1942 and Vietnam days.
Check them out here: Alternative Battlefield Ranking News