WordPress: Tell Search Engines Not to Index Archives

If you run a WordPress [1], and you to search Google’s index using the site parameter – namely, site:%yourdomain% – you’ll probably find that Google has also indexed all of the archives, categories, and tags of your site. For many, the first impulse is to delete this from Google somehow or maybe use robots.txt, or some other method. But, I’ve found the solution is easier, and I’ll show you how to do it (without a plugin).