Standalone Mode
Out of the box, in the stadanlone mode, SonarLint uses a set of default rules. You can find the list of rules in the SonarLint webpage.
Update: You can now configure the rules in the settings.
Connected Mode
It is possible to bind projects to a SonarQube server, and use its Quality Profiles, allowing to customize the rules being used and share the rule set within a team.
On top of that, any known issue in SonarQube that is marked as false positive
or won't fix
will not be displayed in SonarLint.
Finally, even though we don't promote this feature, you can always add a //NOSONAR
as a comment to hide issues.
Changing Highlighting
By default, issues created by SonarLint are highlighted as warnings in IntelliJ, but it can be changed in the following location: Settings > Editor > Colors & Fonts > SonarLint
.
It can be useful to make it more clear what SonarLint is contributing with.
Giving Feedback
It would be great if you could show concrete examples of false positives. The rules are constantly being improved, as you can see in this tracker, and feedback is always appreciated.
You can open a topic here about false positives.