This question already has an answer here:
Every morning I click on the unanswered link and every morning I see many of questions answered in the comments section. When this happens, person who asked the question cannot mark it as answered, it cannot be upvoted and it looks like there are much more unanswered questions then there should be.
Are there any guidelines for this? Am I the only one bothered by this?
[Update after Zanna comment] I believe this is a little different topic. What I am talking about is when there are correct legitimate answers in comments. You can even see next comment from requester saying thank you it worked. But this will be never marked as answered and/or upvoted.