WordPress Custom Post Types Adding Custom Post Types to Main RSS Feed


Registering a custom post type does not mean it gets added to the main RSS feed automatically.You need to use request filter to add custom post types to main RSS feed.

// Add 'books' custom post types on main RSS feed
function add_book_post_types_to_rss($qv) {
    if (isset($qv['feed']) && !isset($qv['post_type']))
        $qv['post_type'] = array('post', 'books', );
    return $qv;
add_filter('request', 'add_book_post_types_to_rss');