fixes #9663: third part, document the resets

_includes/nav-css.html

@@ -20,7 +20,7 @@
     <li><a href="#grid-example-basic">Ex: Stacked-to-horizonal</a></li>
     <li><a href="#grid-example-mixed">Ex: Mobile-desktop</a></li>
     <li><a href="#grid-example-mixed-complete">Ex: Mobile, tablet, desktop</a></li>
-    <li><a href="#grid-responsive-clearing">Responsive column clearing</a></li>
+    <li><a href="#grid-responsive-resets">Responsive column resets</a></li>
     <li><a href="#grid-offsetting">Offset columns</a></li>
     <li><a href="#grid-nesting">Nested columns</a></li>
     <li><a href="#grid-column-ordering">Column ordering</a></li>

css.html

@@ -322,7 +322,7 @@ base_url: "../"
       <p><a class="btn btn-danger" target="_blank" href="http://examples.getbootstrap.com/grid/">More grid examples</a></p>
     </div>
 
-    <h3 id="grid-responsive-clearing">Responsive column clearing</h3>
+    <h3 id="grid-responsive-resets">Responsive column resets</h3>
     <p>With the four tiers of grids available you're bound to run into issues where, at certain breakpoints, your columns don't clear quite right as one is taller than the other. To fix that, use a combination of a <code>.clearfix</code> and our <a href="../css#responsive-utilities">responsive utility classes</a>.</p>
 {% highlight html %}
 <div class="row">
@@ -336,6 +336,19 @@ base_url: "../"
   <div class="col-xs-6 col-sm-3">.col-xs-6 .col-sm-3</div>
 </div>
 {% endhighlight %}
+    <p>In addition to column clearing at responsive breakpoints, you may need to <strong>reset offsets, pushes, or pulls</strong>. Those resets are available for medium and large grid tiers only, since they start only at the (second) small grid tier.</p>
+{% highlight html %}
+<div class="row">
+  <div class="col-sm-5 col-md-6">.col-sm-5 .col-md-6</div>
+  <div class="col-sm-5 col-sm-offset-2 col-md-6 col-md-offset-0">.col-sm-5 .col-sm-offset-2 .col-md-6 .col-md-offset-0</div>
+</div>
+
+<div class="row">
+  <div class="col-sm-6 col-md-5 col-lg-6">.col-sm-6 .col-md-5 .col-lg-6</div>
+  <div class="col-sm-6 col-md-5 col-md-offset-2 col-lg-6 col-lg-offset-0">.col-sm-6 .col-md-5 .col-md-offset-2 .col-lg-6 .col-lg-offset-0</div>
+</div>
+{% endhighlight %}
+
 
     <h3 id="grid-offsetting">Offsetting columns</h3>
     <p>Move columns to the right using <code>.col-md-offset-*</code> classes. These classes increase the left margin of a column by <code>*</code> columns. For example, <code>.col-md-offset-4</code> moves <code>.col-md-4</code> over four columns.</p>