WordPress Fix HTML5 Validation
This section describes how to install the plugin and get it working.
Best to just install through the WordPress admin panel.
Please note: If you're using any plugin that caches content, you must navigate to your cache plugin settings and hit "Flush Cache". Otherwise rel="category tag" will be returned for every cached page, until each page expires (exceeds your cache timeout).
If you're using a front-end caching system like Varnish, best just flush all content. If you're savvy enough to be running Varnish, you'll understand how to do this.
You can also manually install this plugin, via the normal...
<?php do_action('plugin_name_hook'); ?>in your templates