The Participation Guidelines and the signature editor found in the Member Control Panel have been updated.
Before the upgrade to the boards earlier this year, there was a feature on the signature editor that checked signatures to ensure they followed the Participation Guidelines. That feature was lost during the upgrade and had to be recreated from scratch to work with the new boards. Now the feature has been restored and will again check signatures on submission. Members with signatures should check them soon to ensure they fit within the rules.
Speaking of which, the signature rules have moved from the Participation Guidelines to the signature editor. You'll see them below the editor, clearly marked. These are enforced by the board software now, so I'm no longer considering them part of the Guidelines, just like avatar sizes aren't in the Guidelines.
I also added item #13, about contacting site staff about violations instead of responding, to the Guidelines.