Jenkins apparently has code style rules listed in the central wiki at https://wiki.jenkins.io/display/JENKINS/Code+Style+Guidelines. The central wiki seems to be no longer maintained and content seems to be migrated to specific project.

It'd maintain and provide code style in configuration files for common static analysis tools, like checkstyle and PMD which can then be used in the vast number of projects, components and community-maintained repositories. A documentation would no longer be necessary and information and discussion could take place in the configuration file repository and it's issue tracker.