"Postal voting and proxy voting are permitted in countries throughout the western world, but the pattern varies considerably. Postal voting, for instance, may be widespread in one country and prohibited in another owing to the danger of fraud. It should be allowed only if the postal service is secure – in other words, safe from intentional interference – and reliable, in the sense that it functions properly. Proxy voting is permissible only if subject to very strict rules, again in order to prevent fraud; the number of proxies held by any one elector must be limited. "