Once the polls have opened, the role of the media changes from what it was during the campaign period - and specific rules may be devised to govern this shift. In practice, the shift may have taken place earlier, with an embargo placed on political campaign reporting, opinion poll reporting, direct access broadcasts, or advertisements - or all of these.

Many countries, whether by law or custom, have a period when no news of the election is reported through the media. It is very common for this to be the case once voting itself has started. This is analogous with the usual prohibitions on campaigning within the vicinity of a polling station. The United Kingdom, for example, has a customary and voluntary abstention from reporting election campaigning on polling day itself, and many Commonwealth countries observe a similar practice.

Perhaps the best-known example of an obligatory reflection period is France, where it lasts for seven days. Italy and Sweden are other countries where this news blackout is prescribed by law, in both cases for one day before polling. Denmark also has a one-day blackout before polling day, but in that case it is traditional and not legally binding.

Without question, the country with the most extensive news blackout is Israel, where television (though not radio) is prohibited from showing political campaigning for at least 30 days before the election.

The issues posed by a ban on reporting during the poll become proportionally more complex depending on how long the voting takes, as well as how large the country is. In the later case, if the electorate is voting across several time zones, this poses especially complex issues since results in one zone may become available before voting has finished in another.

In essence there are two issues at stake:

• Preserving the integrity of the electoral process and the security of the vote
• Ensuring that the untimely release of information does not influence the vote in any way

The first of these is more straightforward than the second. It is usually not difficult to strike a balance between allowing the media some sort of special access to report on the voting process, but ensuring that voters' secrecy and security is not breached.

However, ensuring the maximum transparency and flow of information without improperly interfering with the process is more difficult, and a greater variety of approaches have been adopted.