Board Thread:Support Requests - Community Management/@comment-7981828-20130825001301/@comment-5085186-20130825031532

If you use forums, you could do a highlighted forum with the policy. All registered users would receive a notification so they would see it at least once. I assume only registered users can add the content?

You could also update your greeting to new users (registered or not) that explains the importance of following this particular rule.