What are your “hard rules” about commenting your code?

Question

I have seen the other questions but I am still not satisfied with the way this subject is covered.

I would like to extract a distiled list of things

Answer 1

When you're writing comments, stop, reflect and ask yourself if you can change the code so that the comments aren't needed. Could you change some variable, class or method names to make things clearer? Would some asserts or other error checks codify your intentions or expectations? Could you split some long sections of code into clearly named methods or functions? Comments are often a reflection of our inability to write (a-hem, code) clearly. It's not always easy to write clearly with computer languages but take some time to try... because code never lies.

P.S. The fact that you use quotes around "hard rules" is telling. Rules that aren't enforced aren't "hard rules" and the only rules that are enforced are in code.