src/Support/RuleListTrait.php
protected function isRemoteRule($rule)
    {
        return in_array($rule, $this->serverRules) ||
            ! in_array($rule, $this->clientRules);
    }
protected function isRemoteRule($rule)
    {
        return in_array($rule, $this->serverRules) ||
            ! in_array($rule, $this->clientRules);
    }
Check if rule must be validated in server-side.

@param $rule
@return bool