Index: wp-app.php
===================================================================
--- wp-app.php	(revision 18052)
+++ wp-app.php	(working copy)
@@ -614,7 +614,7 @@
 			$slug = substr( md5( uniqid( microtime() ) ), 0, 7);
 		$ext = preg_replace( '|.*/([a-z0-9]+)|', '$1', $_SERVER['CONTENT_TYPE'] );
 		$slug = sanitize_file_name( "$slug.$ext" );
-		$file = wp_upload_bits( $slug, NULL, $bits);
+		$file = wp_upload_bits( $slug, null, $bits);
 
 		log_app('wp_upload_bits returns:',print_r($file,true));
 
@@ -1072,10 +1072,10 @@
 
 		log_app('function',"total_count(# $wp_query->max_num_pages #)");
 		$last_page = $wp_query->max_num_pages;
-		$next_page = (($page + 1) > $last_page) ? NULL : $page + 1;
-		$prev_page = ($page - 1) < 1 ? NULL : $page - 1;
-		$last_page = ((int)$last_page == 1 || (int)$last_page == 0) ? NULL : (int) $last_page;
-		$self_page = $page > 1 ? $page : NULL;
+		$next_page = (($page + 1) > $last_page) ? null : $page + 1;
+		$prev_page = ($page - 1) < 1 ? null : $page - 1;
+		$last_page = ((int)$last_page == 1 || (int)$last_page == 0) ? null : (int) $last_page;
+		$self_page = $page > 1 ? $page : null;
 ?><feed xmlns="<?php echo $this->ATOM_NS ?>" xmlns:app="<?php echo $this->ATOMPUB_NS ?>" xml:lang="<?php echo get_option('rss_language'); ?>" <?php do_action('app_ns'); ?> >
 <id><?php $this->the_entries_url() ?></id>
 <updated><?php echo mysql2date('Y-m-d\TH:i:s\Z', get_lastpostmodified('GMT'), false); ?></updated>
@@ -1526,7 +1526,7 @@
 				global $post;
 				$post = wp_get_single_post($this->params[1]);
 				$wp_last_modified = get_post_modified_time('D, d M Y H:i:s', true);
-				$post = NULL;
+				$post = null;
 				break;
 			case $this->ENTRIES_PATH:
 				$wp_last_modified = mysql2date('D, d M Y H:i:s', get_lastpostmodified('GMT'), 0).' GMT';
Index: wp-includes/functions.wp-scripts.php
===================================================================
--- wp-includes/functions.wp-scripts.php	(revision 18052)
+++ wp-includes/functions.wp-scripts.php	(working copy)
@@ -41,7 +41,7 @@
  * @param string $handle Script name
  * @param string $src Script url
  * @param array $deps (optional) Array of script names on which this script depends
- * @param string|bool $ver (optional) Script version (used for cache busting), set to NULL to disable
+ * @param string|bool $ver (optional) Script version (used for cache busting), set to null to disable
  * @param bool $in_footer (optional) Whether to enqueue the script before </head> or before </body>
  * @return null
  */
Index: wp-includes/pomo/mo.php
===================================================================
--- wp-includes/pomo/mo.php	(revision 18052)
+++ wp-includes/pomo/mo.php	(working copy)
@@ -53,7 +53,7 @@
 			$originals_table .= $this->export_original($entry) . chr(0);
 			$length = strlen($this->export_original($entry));
 			fwrite($fh, pack('VV', $length, $current_addr));
-			$current_addr += $length + 1; // account for the NULL byte after
+			$current_addr += $length + 1; // account for the null byte after
 		}
 
 		$exported_headers = $this->export_headers();
Index: wp-includes/comment.php
===================================================================
--- wp-includes/comment.php	(revision 18052)
+++ wp-includes/comment.php	(working copy)
@@ -1116,7 +1116,7 @@
 
 	$approved = $comment->comment_approved;
 
-	if ( $approved == NULL )
+	if ( $approved == null )
 		return false;
 	elseif ( $approved == '1' )
 		return 'approved';
Index: wp-includes/functions.php
===================================================================
--- wp-includes/functions.php	(revision 18052)
+++ wp-includes/functions.php	(working copy)
@@ -1395,7 +1395,7 @@
 			$k = $prefix.$k;
 		if ( !empty($key) )
 			$k = $key . '%5B' . $k . '%5D';
-		if ( $v === NULL )
+		if ( $v === null )
 			continue;
 		elseif ( $v === FALSE )
 			$v = '0';
@@ -1408,7 +1408,7 @@
 			array_push($ret, $k.'='.$v);
 	}
 
-	if ( NULL === $sep )
+	if ( null === $sep )
 		$sep = ini_get('arg_separator.output');
 
 	return implode($sep, $ret);
Index: wp-includes/comment-template.php
===================================================================
--- wp-includes/comment-template.php	(revision 18052)
+++ wp-includes/comment-template.php	(working copy)
@@ -769,7 +769,7 @@
  * @param int $post_id An optional post ID to check instead of the current post.
  * @return bool True if the comments are open
  */
-function comments_open( $post_id=NULL ) {
+function comments_open( $post_id = null ) {
 
 	$_post = get_post($post_id);
 
@@ -786,7 +786,7 @@
  * @param int $post_id An optional post ID to check instead of the current post.
  * @return bool True if pings are accepted
  */
-function pings_open( $post_id = NULL ) {
+function pings_open( $post_id = null ) {
 
 	$_post = get_post($post_id);
 
Index: wp-includes/shortcodes.php
===================================================================
--- wp-includes/shortcodes.php	(revision 18052)
+++ wp-includes/shortcodes.php	(working copy)
@@ -206,7 +206,7 @@
 		return $m[1] . call_user_func( $shortcode_tags[$tag], $attr, $m[5], $tag ) . $m[6];
 	} else {
 		// self-closing tag
-		return $m[1] . call_user_func( $shortcode_tags[$tag], $attr, NULL,  $tag ) . $m[6];
+		return $m[1] . call_user_func( $shortcode_tags[$tag], $attr, null,  $tag ) . $m[6];
 	}
 }
 
Index: wp-includes/functions.wp-styles.php
===================================================================
--- wp-includes/functions.wp-styles.php	(revision 18052)
+++ wp-includes/functions.wp-styles.php	(working copy)
@@ -45,7 +45,7 @@
  * @param string|bool $src Path to the stylesheet from the root directory of WordPress. Example: '/css/mystyle.css'.
  * @param array $deps Array of handles of any stylesheet that this stylesheet depends on.
  *  (Stylesheets that must be loaded before this stylesheet.) Pass an empty array if there are no dependencies.
- * @param string|bool $ver String specifying the stylesheet version number. Set to NULL to disable.
+ * @param string|bool $ver String specifying the stylesheet version number. Set to null to disable.
  *  Used to ensure that the correct version is sent to the client regardless of caching.
  * @param string $media The media for which this stylesheet has been defined.
  */
Index: wp-includes/class-wp-xmlrpc-server.php
===================================================================
--- wp-includes/class-wp-xmlrpc-server.php	(revision 18052)
+++ wp-includes/class-wp-xmlrpc-server.php	(working copy)
@@ -3083,7 +3083,7 @@
 			$name = "wpid{$old_file->ID}-{$filename}";
 		}
 
-		$upload = wp_upload_bits($name, NULL, $bits);
+		$upload = wp_upload_bits($name, null, $bits);
 		if ( ! empty($upload['error']) ) {
 			$errorString = sprintf(__('Could not write file %1$s (%2$s)'), $name, $upload['error']);
 			logIO('O', '(MW) ' . $errorString);
Index: wp-includes/cache.php
===================================================================
--- wp-includes/cache.php	(revision 18052)
+++ wp-includes/cache.php	(working copy)
@@ -422,7 +422,7 @@
 		if ( empty ($group) )
 			$group = 'default';
 
-		if ( NULL === $data )
+		if ( null === $data )
 			$data = '';
 
 		if ( is_object($data) )
Index: wp-includes/query.php
===================================================================
--- wp-includes/query.php	(revision 18052)
+++ wp-includes/query.php	(working copy)
@@ -2923,7 +2923,7 @@
 		if ( isset($this->queried_object) )
 			return $this->queried_object;
 
-		$this->queried_object = NULL;
+		$this->queried_object = null;
 		$this->queried_object_id = 0;
 
 		if ( $this->is_category || $this->is_tag || $this->is_tax ) {
Index: wp-includes/kses.php
===================================================================
--- wp-includes/kses.php	(revision 18052)
+++ wp-includes/kses.php	(working copy)
@@ -937,7 +937,7 @@
 }
 
 /**
- * Removes any NULL characters in $string.
+ * Removes any null characters in $string.
  *
  * @since 1.0.0
  *
Index: wp-admin/includes/plugin.php
===================================================================
--- wp-admin/includes/plugin.php	(revision 18052)
+++ wp-admin/includes/plugin.php	(working copy)
@@ -863,7 +863,7 @@
  *
  * @return string The resulting page's hook_suffix
  */
-function add_menu_page( $page_title, $menu_title, $capability, $menu_slug, $function = '', $icon_url = '', $position = NULL ) {
+function add_menu_page( $page_title, $menu_title, $capability, $menu_slug, $function = '', $icon_url = '', $position = null ) {
 	global $menu, $admin_page_hooks, $_registered_pages, $_parent_pages;
 
 	$menu_slug = plugin_basename( $menu_slug );
Index: wp-admin/includes/post.php
===================================================================
--- wp-admin/includes/post.php	(revision 18052)
+++ wp-admin/includes/post.php	(working copy)
@@ -1193,7 +1193,7 @@
  * @param int $thumbnail_id ID of the attachment used for thumbnail
  * @return string html
  */
-function _wp_post_thumbnail_html( $thumbnail_id = NULL ) {
+function _wp_post_thumbnail_html( $thumbnail_id = null ) {
 	global $content_width, $_wp_additional_image_sizes, $post_ID;
 	$set_thumbnail_link = '<p class="hide-if-no-js"><a title="' . esc_attr__( 'Set featured image' ) . '" href="' . esc_url( get_upload_iframe_src('image') ) . '" id="set-post-thumbnail" class="thickbox">%s</a></p>';
 	$content = sprintf($set_thumbnail_link, esc_html__( 'Set featured image' ));
Index: wp-admin/includes/template.php
===================================================================
--- wp-admin/includes/template.php	(revision 18052)
+++ wp-admin/includes/template.php	(working copy)
@@ -2164,7 +2164,7 @@
  *                     Defaults to no other attributes. Other attributes can also be provided as a
  *                     string such as 'tabindex="1"', though the array format is typically cleaner.
  */
-function submit_button( $text = NULL, $type = 'primary', $name = 'submit', $wrap = true, $other_attributes = NULL ) {
+function submit_button( $text = null, $type = 'primary', $name = 'submit', $wrap = true, $other_attributes = null ) {
 	echo get_submit_button( $text, $type, $name, $wrap, $other_attributes );
 }
 
@@ -2185,7 +2185,7 @@
  *                     Defaults to no other attributes. Other attributes can also be provided as a
  *                     string such as 'tabindex="1"', though the array format is typically cleaner.
  */
-function get_submit_button( $text = NULL, $type = 'primary', $name = 'submit', $wrap = true, $other_attributes = NULL ) {
+function get_submit_button( $text = null, $type = 'primary', $name = 'submit', $wrap = true, $other_attributes = null ) {
 	switch ( $type ) :
 		case 'primary' :
 		case 'secondary' :
@@ -2197,7 +2197,7 @@
 		default :
 			$class = $type; // Custom cases can just pass in the classes they want to be used
 	endswitch;
-	$text = ( NULL == $text ) ? __( 'Save Changes' ) : $text;
+	$text = ( null == $text ) ? __( 'Save Changes' ) : $text;
 
 	// Default the id attribute to $name unless an id was specifically provided in $other_attributes
 	$id = $name;