(Apologies in advance if this seems confusing -- English isn't my first language.)
I can't remember the exact name for it, but what it does is sort of allow you to re-assign a specific file in the torrent to a different file you have. I've already uninstalled uTorrent so I can't verify the command name.
For example, I downloaded the Zenki series off of a different tracker a while back and renamed the episodes to fit with my way of organizing my files. Then, when I joined BakaBT and saw that I had the same files as the ones here, I pointed uTorrent towards my files, set the equivalents for each file, used Force Re-check, and started seeding.
I was wondering if Tixati had a similar setting, but apparently it's something uTorrent-specific.