Admin/local/codechecker/index
From Learnit docs
The Code Checker plugin for Moodle checks for Coding style errors and warnings.
If anything you should be looking for errors only, warnings are recommendations, basically. while errors are clear violations, warnings can be understood as recommendations. If you decide to follow or ignore them it's up to you to follow them, it's not so hard, really. But your choice, anyway.
The comment style is really not important.
See also
This forum thread about Moodle coding style.
