It would be lovely to have a link, banner, or area to have a code of conduct. As a public forum and board it would be nice to encourage customers to be positive and privately handle any angry customers.
This would limit the negative comments (they are going to happen) should someone feel like they need to attack the company or an employee. We have a terms of use already but can't link this as a one time reminder.
Something like the removable banner tip you have for inviting teammates to canny.