Forgive me if this has been asked for before, but I didn't see it when I skimmed through this thread...
Would it be possible to tag series that are cancelled or abandoned by either the author or the scanlators? There's nothing worse than getting to the end of a really really good manga (like, for example, Flower Flower or Gretel) and finding out (only after reading the related thread) that there will never be a continuation. I know that it is usually marked at the top of the individual manga's page, but if you search on tags, sometimes you jump into the middle of the series, read a little, and then jump back to the first chapter and read through, all without ever seeing the manga's page.
No need to separate out with one tag for cancelled and one for abandoned. Just a simple tag saying Series cut short
or just no end
would do the trick.