Navigation view helper plugin prepends the normalised name of the plugin to the id of a page, if specified

menu.phtml

<?php /* @var $container Zend\Navigation\Navigation */ ?>
<?php if ($container->hasPages()): ?>
<ul>
    <?php foreach ($container->getPages() as $page): ?>
        <?php /* @var $page Zend\Navigation\Page\AbstractPage */ ?>
        <?php if ($page->isVisible()): ?>
    <li><?php echo $this->navigation()->menu()->htmlify($page); ?></li>
        <?php endif; ?>
    <?php endforeach; ?>
</ul>
<?php endif; ?>

module.config.php

<?php

return array(
    'navigation' => array(
        'default' => array(
            'example' => array(
                'label' => 'Example',
                'id' => 'example',
                'uri' => '#',
            ),
        ),
    ),
);

result-actual.html

<ul>
    <li><a href="#" id="menu-example">Example</a></li>
</ul>

result-expected.html

<ul>
    <li><a href="#" id="example">Example</a></li>
</ul>