Should employers have written rules on work-related social events?

It is a good idea for employers to provide clear written guidance to all employees about acceptable standards of behaviour at work-related social events - and the disciplinary sanctions that could result from breaches of the rules. While it might be unreasonable to expect employees to stay completely sober, a statement that only moderate alcohol consumption is acceptable should be included. Fighting, the use of illegal drugs and inappropriate language should also be prohibited.