添加品牌作为分类：

if ( ! function_exists( \'brand_tax\' ) ) {

// Register Custom Taxonomy
function brand_tax() {

    $labels = array(
        \'name\'                       => _x( \'Brands\', \'Taxonomy General Name\', \'text_domain\' ),
        \'singular_name\'              => _x( \'Brand\', \'Taxonomy Singular Name\', \'text_domain\' ),
        \'menu_name\'                  => __( \'Brands\', \'text_domain\' ),
        \'all_items\'                  => __( \'All brands\', \'text_domain\' ),
        \'parent_item\'                => __( \'Parent brand\', \'text_domain\' ),
        \'parent_item_colon\'          => __( \'Parent brand:\', \'text_domain\' ),
        \'new_item_name\'              => __( \'New brand\', \'text_domain\' ),
        \'add_new_item\'               => __( \'Add New brand\', \'text_domain\' ),
        \'edit_item\'                  => __( \'Edit brand\', \'text_domain\' ),
        \'update_item\'                => __( \'Update brand\', \'text_domain\' ),
        \'view_item\'                  => __( \'View brand\', \'text_domain\' ),
        \'separate_items_with_commas\' => __( \'Separate brands with commas\', \'text_domain\' ),
        \'add_or_remove_items\'        => __( \'Add or remove brands\', \'text_domain\' ),
        \'choose_from_most_used\'      => __( \'Choose from the most used\', \'text_domain\' ),
        \'popular_items\'              => __( \'Popular brands\', \'text_domain\' ),
        \'search_items\'               => __( \'Search brands\', \'text_domain\' ),
        \'not_found\'                  => __( \'Not Found\', \'text_domain\' ),
        \'no_terms\'                   => __( \'No brands\', \'text_domain\' ),
        \'items_list\'                 => __( \'brands list\', \'text_domain\' ),
        \'items_list_navigation\'      => __( \'brands list navigation\', \'text_domain\' ),
    );
    $args = array(
        \'labels\'                     => $labels,
        \'hierarchical\'               => true,
        \'public\'                     => true,
        \'show_ui\'                    => true,
        \'show_admin_column\'          => true,
        \'show_in_nav_menus\'          => true,
        \'show_tagcloud\'              => true,
    );
    register_taxonomy( \'brand\', array( \'product\' ), $args );

}
add_action( \'init\', \'brand_tax\', 0 );

}

add_filter( \'the_title\', \'custom_the_title\', 10, 2 );  
function custom_the_title( $title, $post_id ) {      
    $post_type = get_post_field( \'post_type\', $post_id, true );  
    if( $post_type == \'product\' ){
        $terms = get_the_terms( $post_id, \'brand\' );
        foreach($terms as $term){
            $output .=  "<span>".$term->name."</span>";
        }
        $title .= "<br><p>".$output ."</p>";
    }
    return $title;  
}