<p dir="auto">When you have a prepended or appended like this below on a form-inline it brokes.</p>
<div class="snippet-clipboard-content notranslate position-relative overflow-auto" data-snippet-clipboard-copy-content="&lt;div class=&quot;input-prepend&quot;&gt;
    &lt;span class=&quot;add-on&quot;&gt;@&lt;/span&gt;
    &lt;input class=&quot;span2&quot; id=&quot;prependedInput&quot; size=&quot;16&quot; type=&quot;text&quot;&gt;
&lt;/div&gt;"><pre class="notranslate"><code class="notranslate">&lt;div class="input-prepend"&gt;
    &lt;span class="add-on"&gt;@&lt;/span&gt;
    &lt;input class="span2" id="prependedInput" size="16" type="text"&gt;
&lt;/div&gt;
</code></pre></div>
<p dir="auto">If use "input-append" then "help-inline" not center vertical</p>
<div class="snippet-clipboard-content notranslate position-relative overflow-auto" data-snippet-clipboard-copy-content="&lt;form method=&quot;post&quot; class=&quot;form-horizontal&quot;&gt;
  &lt;fieldset&gt;
&lt;div class=&quot;control-group&quot;&gt;
  &lt;label  class=&quot;control-label&quot; for=&quot;appendedInput&quot;&gt;Appended text&lt;/label&gt;
  &lt;div class=&quot;controls&quot;&gt;
    &lt;div class=&quot;input-append&quot;&gt;
      &lt;input type=&quot;text&quot; class=&quot;medium&quot; id=&quot;appendedInput&quot; name=&quot;appendedInput&quot; size=&quot;16&quot;&gt;
      &lt;span class=&quot;add-on&quot;&gt;%&lt;/span&gt;&lt;span class=&quot;help-inline&quot;&gt;not center&lt;/span&gt;
    &lt;/div&gt;
    &lt;span class=&quot;help-block&quot;&gt;Here's some help text&lt;/span&gt;
  &lt;/div&gt;
&lt;/div&gt;
 &lt;/fieldset&gt; 
&lt;/form&gt;"><pre class="notranslate"><code class="notranslate">&lt;form method="post" class="form-horizontal"&gt;
  &lt;fieldset&gt;
&lt;div class="control-group"&gt;
  &lt;label  class="control-label" for="appendedInput"&gt;Appended text&lt;/label&gt;
  &lt;div class="controls"&gt;
    &lt;div class="input-append"&gt;
      &lt;input type="text" class="medium" id="appendedInput" name="appendedInput" size="16"&gt;
      &lt;span class="add-on"&gt;%&lt;/span&gt;&lt;span class="help-inline"&gt;not center&lt;/span&gt;
    &lt;/div&gt;
    &lt;span class="help-block"&gt;Here's some help text&lt;/span&gt;
  &lt;/div&gt;
&lt;/div&gt;
 &lt;/fieldset&gt; 
&lt;/form&gt;
</code></pre></div>
<p dir="auto">Opera</p>