I am not certain that I agree with this. If there are alternative ways of solving a problem that we're not taken then these should be documented in comments. A mantra I try to tell myself and my colleagues is if information exists in your brain and nowhere else then write down it down _somewhere_. If I tried 5 different libraries before settling on one, then I write in comments which libraries I tried but didn't work and why. If I used a particular tool to debug a race condition then I put a link to a wiki page on how to use it in the comments. If we have one particular colleague who is an expert in some area then I write their name in a comment. Basically anything that is going to save future developers' time should be written down.