Idea: A flag for any user to mark "This question has an acceptable answer."
How it works: Anyone reviewing a question and all answers and comments that follow it can mark this flag. It means someone thought the question has an answer.
But... upvoting and accept! Upvoting is great. It's great when authors accept. That should not change one iota. This is just a proposal for a no-rep counter.
What problem does this solve? I'm looking for questions that have not been answered or have no accepted answers. I find a question that does not have an accepted answer. There is a great answer in the comments or an actual answer. It all happened a long time ago. No one involved in the asking or answering cares anymore. I want to mark this and move on.
Does this break the system? No. It's really meant to be a small, rep-less thing that just helps with search filtering. It is purposefully not meant to break the axioms that comments are not acceptable as answers and the author is the all-powerful acceptor.
People seem pretty passionate about the subject, so I present this humbly and will not lose sleep if you shoot this down. A lot of you have a LOT more experience on this site than I do.
EDIT Added that I'm not just looking for no-answers, but no accepted answers, i.e. questions that appear to not have been adequately answered.