For every function, it's great to have a plain language comment explaining What it does and Why it does it. You can also include How it works (if it's sufficien

For every function, it's great to have a plain language comment explaining What it does and Why it does it. You can also include How it works (if it's sufficiently complex), and When you expect it to get called if you want. If you care at all about your future self, or others who have to look at your code, the best way to help is to leave a verbose history.