why use text indent 0 in this code.?

<div class="requirements" id="zen-requirements" role="article">
            <h3>Requirements</h3>
<p>This is a learning exercise as well as a demonstration. You retain full copyright on your graphics (with limited exceptions, see <a href="http://www.mezzoblue.com/zengarden/submit/guidelines/">submission guidelines</a>), but we ask you release your <abbr title="Cascading Style Sheets">CSS</abbr> under a Creative Commons license identical to the <a href="http://creativecommons.org/licenses/by-nc-sa/3.0/" title="View the Zen Garden's license information.">one on this site</a> so that others may learn from your work.</p>
            <p role="contentinfo">By <a href="http://www.mezzoblue.com/">Dave Shea</a>. Bandwidth graciously donated by <a href="http://www.mediatemple.net/">mediatemple</a>. Now available: <a href="http://www.amazon.com/exec/obidos/ASIN/0321303474/mezzoblue-20/">Zen Garden, the book</a>.</p>
        </div>

.requirements p:last-of-type {
  max-width: 92%;
  text-align: center;
  font-style: italic;
  text-indent: 0;
  padding-top: 4em;
  color: #6d6f81;

}