Extended File List, keep track of files that you have in offline storage

Allow you to store the TTH (and metadata) for files that you are not currently sharing that are on removable media. DC++ allows you to hide files already in share, but you might have downloaded and copied off to backup storage. It would also allow DC++ to act as a database of all the files you have and where they are stored. You should also be able to specify you have a file that you find in a share result (ie, you have a particular mp3 of a track, another rip would have a different tth but you don't want it to keep popping up when you do a search).