title: What is the at sign (@) in a batch file and what does it do?
body: <p>One remotely familiar with windows/dos batch scripting will recognize this line:</p>
  
  <pre><code>@echo off
  </code></pre>
  
  <p>For many-many days, I was happy with the sentiment that the <code>@</code> is how <code>echo off</code> is meant to be written at the top of the batch and that's it.</p>
  
  <p>However, recently I've <a href="http://getcomposer.org/doc/00-intro.md#manual-installation" rel="noreferrer">came accross</a> a line like this:</p>
  
  <pre><code>@php foo bar
  </code></pre>
  
  <p>and <a href="https://superuser.com/a/470468">another line</a> like this:</p>
  
  <pre><code>@call \\network\folder\batch.bat
  </code></pre>
  
  <p>This reinforced my suspicion that <code>@</code> has more to it than just <code>echo</code> mode switching. However <code>@</code> is not listed in the <a href="http://technet.microsoft.com/en-us/library/bb490890.aspx" rel="noreferrer">Windows XP: Command-line reference A-Z</a> which I try to use as a reference and thus I'm not sure how to find definitive information on this:</p>
  
  <p><strong>What is the <code>@</code> sign in batch, what's the terminology for it, and what does it do?</strong></p>