Add more structure tag to permalink?

=> Create a Custom Taxonomy

First, we create a custom taxonomy object called rating with the register_taxonomy WordPress function.

add_action( 'init', 'my_rating_init' );

function my_rating_init() {
    if ( ! is_taxonomy( 'rating' ) ) {
        register_taxonomy( 
            'rating', 
            'post', 
            array( 
                'hierarchical' => FALSE, 
                'label' => __( 'Rating' ),  
                'public' => TRUE, 
                'show_ui' => TRUE,
                'query_var' => 'rating',
                'rewrite' => true 
            ) 
        );
    }
}

Setting 'rewrite' => true will automatically add the tag %rating% to our WordPress system.