functions.php

remove_action( 'wp_head', 'feed_links_extra', 3 ); // Removes the links to the extra feeds such as category feeds

remove_action( 'wp_head', 'feed_links', 2 ); // Removes links to the general feeds: Post and Comment Feed

remove_action( 'wp_head', 'rsd_link'); // Removes the link to the Really Simple Discovery service endpoint, EditURI link

remove_action( 'wp_head', 'wlwmanifest_link'); // Removes the link to the Windows Live Writer manifest file.

remove_action( 'wp_head', 'index_rel_link'); // Removes the index link

remove_action( 'wp_head', 'parent_post_rel_link'); // Removes the prev link

remove_action( 'wp_head', 'start_post_rel_link'); // Removes the start link

remove_action( 'wp_head', 'adjacent_posts_rel_link'); // Removes the relational links for the posts adjacent to the current post.

remove_action( 'wp_head', 'wp_generator'); // Removes the WordPress version i.e. - WordPress 2.8.4

ที่มา http://rjpargeter.com/2009/09/removing-wordpress-wp_head-elements/