The next step is to fix the code we've identified as the cause for the problem.
<a href="" title="View all posts in Resources" rel="category tag">Resources</a>
the_category()
template tag.category-template.php
file, which is a part of the core WordPress installation (you can see this at http://core.trac.wordpress.org/browser/tags/3.5.1/wp-includes/category-template.php—it's daunting, so be warned!).index.php
file and delete it:in <?php the_category(", ") ?>
index.php
file and repeat the validation process at http://validator.w3.org/.Having identified the offending code, we found out how it was being generated and removed it. If the code is generated by your theme's markup rather than by WordPress, you may find that you can change it instead of deleting it.
If you ever come across problems like this which are thrown up by WordPress, you can always go to the WordPress trac site at http://core.trac.wordpress.org to see if a ticket has been raised about it, or you can submit one yourself. In this case, there is a ticket at http://core.trac.wordpress.org/ticket/17632.
Now let's see what the validator makes of our page: