title: CSS default value of a property
body: <p>So i am reading this book Programming in HTML5 with JavaScript and CSS3 by Microsoft and there is this exercise using tables, there is a css rule to display and hide some elements but only the hidden or actually in css display:none property is working and the display:normal says its an invalid value in css.</p>
  
  <pre><code>.hidden {
      display: none;
  }
  .visible {
      display: normal;
  }
  </code></pre>
  
  <p>Is it possible that this book is actually wrong about the display:normal property or am i doing something wrong?</p>