I wanted to add an introduction text to category pages. I already had a nice looking introduction text to the blog which only shows on the main page, so I thought I’d put the category descriptions in a similar box.

<!-- don’t show on a post’s page or monthly archives -->
<?php if (!$single && !$monthnum) { ?>
  <div id="intro">
    <!-- don’t show on category pages, either -->
    <?php if(!$cat) { ?>
      < Blog introduction >
    <?php } ?>
    <!-- show on category pages -->
    <?php if ($cat) { ?>
      <!-- single_cat_title(prefix,display) displays (with ‘true’ parameter) the category title -->
      <h1><?php single_cat_title('',true); ?></h1>
      <!-- category_description() alone doesn’t display it, that’s why you need to have the ‘echo’ there -->
      <p><?php echo category_description(); ?></p>
    <?php } ?>
  </div>
<?php } ?>