Add nofollow to quicktabs
Unless you want or can modify $qt_project and add in the rel to the attributes array of the links, the only way I see is to add in a custom renderer in your module.

This would entail some ctools integration implementing hook_ctools_plugin_type(), some quicktabs integration implementing hook_quicktabs_renderers() and then basically copying QuickQuicktabs.inc from the quicktabs module to your module's directory structure, changing the name to something appropriate, and then inside, also changing the name of the QuickQuicktabs class to something similar, and then in the guts of that, changing

/**
 * Helper function to construct link options for tab links.
 */
protected function construct_link_options($tabkey) {
  $qt_name = $this-&gt;quickset-&gt;getName();
  $id = 'quicktabs-tab-' . implode('-', array($qt_name, $tabkey));

  // Need to construct the correct querystring for the tab links.
  $query = drupal_get_query_parameters(NULL, array("qt-$qt_name", 'q', 'page'));
  $query["qt-{$qt_name}"] = $tabkey;

  $link_options = array(
    'attributes' =&gt; array(
      'id' =&gt; $id,
    ),
    'query' =&gt; $query,
    'fragment' =&gt; 'qt-' . $qt_name,
  );
  return $link_options;
}


to most probably just

/**
 * Helper function to construct link options for tab links.
 */
protected function construct_link_options($tabkey) {
  $qt_name = $this-&gt;quickset-&gt;getName();
  $id = 'quicktabs-tab-' . implode('-', array($qt_name, $tabkey));

  // Need to construct the correct querystring for the tab links.
  $query = drupal_get_query_parameters(NULL, array("qt-$qt_name", 'q', 'page'));
  $query["qt-{$qt_name}"] = $tabkey;

  $link_options = array(
    'attributes' =&gt; array(
      'id' =&gt; $id,
      'rel' =&gt; 'nofollow',  // just this one little addition :)
    ),
    'query' =&gt; $query,
    'fragment' =&gt; 'qt-' . $qt_name,
  );
  return $link_options;
}


and then calling quicktabs_build_quicktabs() with 'render' pointing to your custom renderer in the $qt_options array.