For their children, Prince William and Kate Middleton have one strict rule.

There is no yelling or shouting allowed.

The family promotes open communication and the expression of emotions.

When people raise their voices, communication comes to a halt.

The couple uses a "chat sofa" to take "time out" and talk through their feelings.

The children are never yelled at and are always spoken to calmly.

The Prince and Princess of Wales are also subject to the no-shouting rule.

The family's discipline policy aids in presenting a united parental front.

The rule and chat sofa are intended to promote understanding and problem solving.