First thing before any code review is that your team/company needs to have a coding standard. This is the first rule of engagement and eliminates most problems.

First thing before any code review is that your team/company needs to have a coding standard. This is the first rule of engagement and eliminates most problems. Without a coding standard, code reviews quickly devolve into crap. Once you have a coding standard, then the reviewer needs to differentiate between opinion and fact. If you don't like the variable name but it conforms to the coding standard then it's not a valid review comment. The coding standard should give some guidance as to what a variable name or function name should be. If there's a bug or if there are potential for issues then that's what I focus on.