This post has an answer and 72 up votes, 15k views and is 2 years old bumped up with an answer by SEO
Another post in the meta Are you going on marking community wiki each SEO question?
And someone says
You are commenting on a question which hasn't been active in over a year
Are there guidelines for this? Isn't this a step up from people commenting saying "Thank you" If it's an old question and no answer or selected answer I think it's fine to dig up old questions but ones with a clear answer like that?