Passing Query String Parameters in WordPress URL | SEO Blog by RLM
http://www.rlmseo.com/blog/passing-get-query-string-parameters-in-wordpress-url/
Whenever possible, I prefer to use pretty URLs in WordPress, and the ability to adjust permalink settings in the WordPress admin makes that simple to do. However, what if you want to pass a query string to a page without muddying up the URL with that query string? In this tutorial I’ll show you how to add custom rewrite rules to WordPress to do just that.