title: Does anyone know how/why this "every SIM card has a name" thing works?
body: <p>I've seen pictures like this on Facebook:</p>
  
  <p><img src="https://i.stack.imgur.com/obMsB.jpg" alt="enter image description here"></p>
  
  <p>The instructions claim that your SIM card has a unique name that can be displayed by inputting a command of the form</p>
  
  <pre><code>@[x:0]
  </code></pre>
  
  <p>where <code>x</code> is the last 3 digits of your phone number.</p>
  
  <p>I don't believe for a second this has anything to do with your phone number/SIM card, but it does "work". When I posted the command into a text box  on Facebook it was replaced with a name.</p>
  
  <p>I don't recognise the syntax with the <code>@</code>, but the square brackets makes me think it's some kind of array.</p>
  
  <p>When I enter <code>@[123:0]</code> as a status update, the name <code>Morgan Grice</code> is the output. I wonder if the output name varies based on the user entering the command, or whether <code>@[123:0]</code> always outputs <code>Morgan Grice</code> (difficult for me to find out on my own).</p>
  
  <p>Does anyone know how this is happening and explain how, for example, <code>@[123:0]</code> becomes <code>Morgan Grice</code>? </p>