Method allowCustom

/**
 * Determines if the field allows or denies custom values
 *
 * @return  boolean
 */
public function allowCustom()
{
    if ($this->element['custom'] && \in_array((string) $this->element['custom'], array('0', 'false', 'deny'))) {
        return false;
    }
    return Factory::getUser()->authorise('core.create', 'com_tags');
}