http://framework.zend.com/manual/en/…

According to Example 8.4:

$currency->setFormat(Zend_Currency::USE_NAME&Zend_Currency::RIGHT);
// prints '1.000,00 US Dollar'
echo $currency->toCurrency(1000);

$currency->setFormat("American Dollar");
// prints '1.000,00 American Dollar'
echo $currency->toCurrency(1000);

This is inaccurate, since setFormat() only takes one array argument, according to v1.5.2 (Currency/Currency.php) beginning from line 223:

public function setFormat(array $options = array())
{
    $this->_options = array_merge($this->_options, $this->checkOptions($options));
    return $this;
}