I used to check for missing series tags by typing each individual title in minus their series until I learned of the asterisk. However, within the past few days, searching "final_fantasy_* -final_fantasy" gives me...
"Error: You cannot search for only excluded tags"
... which comes off weird to me, since it would seem that the search is including a partial of the "final_fantasy_*" search or something. Is it a bug? What's causing this, if intended?
Updated