You can use the "attributes" method to access any request attribute by its key:
{% if Request->attributes("internal") %}
<h1>Welcome to our intranet!</h1>
{% else %}
<p>Sorry, this page is for internal use only.</p>
{% endif %}
Request attributes are a special feature of the Symfony framework useful if you want to associate custom data with a request so that it is available throughout the application. It is one possible way of providing data from PHP to a Twig template that cannot be determined by the template itself.