There is also a back-end option that can be used instead of this code.
What is this, and where do I put this custom code?
add_filter( 'asp_query_args', 'asp_include_only_post_ids', 10, 2 );function asp_include_only_post_ids( $args, $id ) {/*** Enter the post IDs here. The results will be* limited to these posts/CPT only.*/$ids = '1, 2, 3, 4, 5';$search_ids = 'all'; // Commma separated list of search IDs, if needed// -- !! Do not change anything below this line !! --$search_ids = wpd_comma_separated_to_array($search_ids);if ( in_array('all', $search_ids) || in_array($id, $search_ids) ) {$ids = wpd_comma_separated_to_array($ids);if ( is_array($args['post_in']) ) {$args['post_in'] = array_unique(array_merge($args['post_in'], $ids));} else {$args['post_in'] = $ids;}}return $args;}
$ids - comma separated list of Post, Page or any custom post type IDs to restrict the results to