location ~* ^/help/(.+\.(woff|svg|jpg|jpeg|gif|png|css|ico|js|html)) {
    proxy_pass $scheme://$backend;
    proxy_cache_key "$uri";
    proxy_cache $cuicdoc_cache;
    add_header X-ReverseProxy-Cache-Status $upstream_cache_status;
    proxy_cache_revalidate on;
    proxy_cache_valid 200 302 2m;
    add_header        Cache-Control "must-revalidate";
    etag on;
}
