This question already has an answer here:
I am aware that unanswered questions with a score of 0 are automatically deleted after 30 days. Does this mean that those questions will be deleted even if they contain useful information that has been posted as a comment, instead of being posted as an answer?
I've noticed that some 0-score unanswered questions contain useful information that has been posted in comments instead of being posted as an answer, and I certainly don't want this information to be lost forever. For example, I got some useful advice from another user in this question here, so I don't want my question to be automatically deleted even if its score never rises above 0.