Reference the relevant line in alertify.js

www/common/common-interface.js

@@ -1,5 +1,6 @@
 if (!document.querySelector("#alertifyCSS")) {
     // Prevent alertify from injecting CSS, we create our own in alertify.less.
+    // see: https://github.com/alertifyjs/alertify.js/blob/v1.0.11/src/js/alertify.js#L414
     var head = document.getElementsByTagName("head")[0];
     var css = document.createElement("span");
     css.id = "alertifyCSS";