Now you may ask: what happens if I put twice the same file in two separate folders? Will Tagsistant create two copies of the same file or what? The answer is: as soon as Tagsistant notices that two files with the same contents have been created, it deletes the second applying its tag set to the first one. So if you do this:

$ mkdir ~/myfiles/tags/movies/
$ mkdir ~/myfiles/tags/startrek/
$ cp first_contact.avi ~/myfiles/tags/movies/@/
$ cp first_contact.avi ~/myfiles/tags/startrek/@/

right after the end of the second copy Tagsistant will compare the content of the two files first_contact.avi, guess the second is a duplicate of the first, delete the second and tag the first also as startrek/. So you can now:

$ ls ~/myfiles/tags/startrek/movies/@/
first_contact.avi the_wrath_of_khan.avi

Deduplication can currently be a bit rough and confusing for the user. If two identical files named A.jpg and B.jpg get copied in two directory called tag1/ and tag2/, Tagsistant will delete B.jpg and tag A.jpg as tag2/ too. So, the content of B.jpg (being identical to A.jpg) is really available under tag2/ too, but as A.jpg! The file tag2/B.jpg seems to have disappeared. This is something Tagsistant will address in a future release.