framework/widgets/LinkPager.php
protected function registerLinkTags()
    {
        $view = $this->getView();
        foreach ($this->pagination->getLinks() as $rel => $href) {
            $view->registerLinkTag(['rel' => $rel, 'href' => $href], $rel);
        }
    }
protected function registerLinkTags()
    {
        $view = $this->getView();
        foreach ($this->pagination->getLinks() as $rel => $href) {
            $view->registerLinkTag(['rel' => $rel, 'href' => $href], $rel);
        }
    }
Registers relational link tags in the html header for prev, next, first and last page.
These links are generated using [[\yii\data\Pagination::getLinks()]].
@see http://www.w3.org/TR/html401/struct/links.html#h-12.1.2