3–5 positive rules, each with a one-line reason, pinned where people arrive.

Three to five rules, written as positives, pinned where new people arrive, each with a one-line reason. In a randomised experiment, posting the rules raised newcomer participation and cut harassment.
S Evidence: strong. Large trials or many studies, pointing the same way.
P Evidence: promising. Good studies, but small or few. Use it and keep checking.
Matias 2019 (field experiment, 2,190 discussions).
Not medical, legal or financial advice.
In The Ecosystem every framework comes with a daily action, a room that checks in, and the full library.