Comments are for revision control systems. We have a strictly no comments in code policy because comments too often end up being wrong or misleading throwing everyone believing in them for a wild ride. The only thing that is worse than bad code is bad comments.
When you read sensible and thorough commit messages you generally have the notion that whatever it says was probably true at the time of the commit, whereas when you read comments in code it can still be correct or just plain utterly wrong.