Windows.open Source Code

On most EVERY commercial site (including the pages on comp.lang.javascript) I find the following code, word for word.

<script language="JavaScript">
<!--

function SymError()
{
return true;
}

window.onerror = SymError;

var SymRealWinOpen = window.open;

function SymWinOpen(url, name, attributes)
{
return (new Object());
}

window.open = SymWinOpen;

//-->
</script>

Is this some "standard" code that every Web page should have. Does it
control the opening of new windows when a user clicks on a newsgroup
message.