title: How to express in two or three letters how a column is to be sorted
body: <p>On a <a href="http://www.sellmycalls.com/cgi-bin/chain" rel="nofollow"><b>just-now-coming-alive web page</b></a>, I have two columns: change and change-percent. In the headers of the two columns, I want to give the user a small control so he can toggle between sorting the columns by abs value; and arithmetically.</p>
  
  <p>In the first case, I can show him something like:</p>
  
  <pre><code> +-----+    +-----+
   | ABS | or | MAG |
   +-----+    +-----+
  </code></pre>
  
  <p>What two- or three-letter abbrev can I give him to select sorting by signed value?</p>
  
  <p>Or what graphics can I use to express the same ideas clearly and with good affordance?</p>
  
  <p>Thanks!</p>