I asked this question about how Unity3D coroutines work -- after fruitlessly Googling and researching on the web. It turns out the (pretty much perfect) answer was a link to a blog post that Kay linked to in a comment. Now that I know about this blog, I don't know why I didn't find it at the time, but I didn't. I asked him to add that link as an answer for the benefit of future SO users. He did and I accepted it.
Then, as I found out later when wanting to look up the link again, his answer disappeared, apparently, as one commenter supposes, because it wasn't considered an answer.
Today, another user has added the answer back (not realizing it may have been deleted). To me, this suggests having the link as an answer is indeed helpful to SO users -- the link was certainly helpful to me.
So -- is the link (as originally answered in Kay's comment) really not an acceptable answer?