fix #11003

getting-started.html

@@ -701,7 +701,11 @@ bootstrap/
     <p>Unofficially, Bootstrap should look and behave well enough in Chromium and Chrome for Linux, Firefox for Linux, and Internet Explorer 7, though they are not officially supported.</p>
 
     <h3>Internet Explorer 8 and 9</h3>
-    <p>Internet Explorer 8 and 9 are also supported, however, please be aware that some CSS3 properties and HTML5 elements are not fully supported by these browsers. In addition, <strong>Internet Explorer 8 requires the use of <a href="https://github.com/scottjehl/Respond">respond.js</a> to enable media query support.</strong></p>
+    <p>Internet Explorer 8 and 9 are also supported, however, please be aware that some CSS3 properties and HTML5 elements are not fully supported by these browsers. In addition, <strong>Internet Explorer 8 requires the use of <a href="https://github.com/scottjehl/Respond">Respond.js</a> to enable media query support.</strong></p>
+    <div class="bs-callout bs-callout-warning" id="respond-js-x-domain">
+      <h4>Respond.js and cross-domain CSS</h4>
+      <p>Using Respond.js with CSS hosted on a different (sub)domain (for example, on a CDN) requires some additional setup. <a href="https://github.com/scottjehl/Respond/blob/master/README.md#cdnx-domain-setup">See the Respond.js docs</a> for details.</p>
+    </div>
     <div class="table-responsive">
       <table class="table table-bordered table-striped">
         <thead>