International law supersedes all codes of conduct, including this one. Authors of codes of conduct presuming the authority to create new laws should be brought to justice.
This being said, if you still insist on wringing advice from us: Be kind. Be professional. Be friendly. Be respectful. Focus on the project. Report inappropriate conduct.
Contributions which fail to conform to these guidelines may be reworded, censored, and/or reported as abuse without notice.
We celebrate the fact that all contributions come from different humans with their own unique attributes, background and history. However we also place a strong emphasis on neutrality and a simple focus on the project's goals. Contributions are thus particularly welcome when references to gender, ethnicity, religion and so on are avoided as much as possible. This is for inclusiveness, professionality, and also privacy and security. This likely means that apart from usernames (which frequently unavoidably hint about the author's background) there should be no personal information included in contributions.
Note that we have no contract with contributors. Introducing contributor licence agreements (CLAs) would allow us to enforce additional rules but would also be a scary barrier for new contributors. We don't want to be scary. We love you!