We (the admins) have had some discussion about implementing a meta tag system, which would basically fulfill this idea. Since then, I added a better search feature in an attempt to sort of relieve the need for such a sorting system, but I still think it would be very much possible in the future. The only problem is the low amount of time I have available to implement such a feature. However, I will keep it on the to-do list and eventually get it implemented. Good idea