Guidelines on giving/receiving code review comments

Central thesis here is that I think "please make this change" isn't "make this change or else". It should invite discussion if you feel strongly that it shouldn't happen.

Thoughts?
* We might possibly consider saying something about clever code and that it's reasonable to make that clever one-liner into something more comprehendible. 
* I'd like to mention Jr. vs. Sr. here too. e.g. "Remember that you have 20 years of programming experience while others are just getting started. It's easy to forget what we've already learned sometimes."