nsupdate.info/nsupdate/templates/includes/base_footer.html

            <p class="text-muted credit">
                <a href="http://github.com/nsupdate-info/nsupdate.info">{% trans "Powered by nsupdate.info" %}</a>
                &nbsp;|&nbsp;
                <a href="http://jigsaw.w3.org/css-validator/check/referer">{% trans "Valid CSS</a>
                <a href="http://validator.w3.org/check/referer">{% trans "Valid HTML" %}</a>
                &nbsp;|&nbsp;
                <a href="http://jigsaw.w3.org/css-validator/check/referer">{% trans "Valid CSS" %}</a>
            </p>