Was closed for over a month, was never improved. It was manually deleted because it has answers, so the automatic clean-up job won't pick this up.
Now, I see it has been undeleted over a month after being deleted, but without being improved to the point that it can be reopened. Why?
It's not even one of those questions we need lying around as a good 'bad example'.
Copied from meta.stackexchange:
What are the criteria for deletion?
For questions, a post that no longer adds anything to the site should be deleted. Basically, this includes most closed questions that cannot be improved and reopened. However, it may be beneficial to keep duplicates to aid future users in finding the canonical question, as different people may use different wordings that cause the canonical question to not show up in search.
The question matches the criteria mentioned there, so why was it undeleted?
The only rule I can find for undeleting a post is this:
If your post was deleted by trusted users, it will require three undelete votes to be undeleted - politely asking for this on Meta may attract the necessary votes if you make a good case for why the question should be restored.
I certainly haven't seen a good case for why the question should be restored, so maybe someone that undeleted the question can enlighten me?
After posting this meta, the question was deleted again. I'm leaving the meta up, because I'd really like to know why it was undeleted, because that might be a point the community need to take into consideration when voting to delete stuff in the first place.