Index: src/wp-admin/menu.php
===================================================================
--- src/wp-admin/menu.php	(revision 25130)
+++ src/wp-admin/menu.php	(working copy)
@@ -53,7 +53,7 @@
 
 	$i = 15;
 	foreach ( get_taxonomies( array(), 'objects' ) as $tax ) {
-		if ( ! $tax->show_ui || ! in_array('post', (array) $tax->object_type, true) )
+		if ( ! $tax->show_ui || ! $tax->show_in_menu || ! in_array('post', (array) $tax->object_type, true) )
 			continue;
 
 		$submenu['edit.php'][$i++] = array( esc_attr( $tax->labels->menu_name ), $tax->cap->manage_terms, 'edit-tags.php?taxonomy=' . $tax->name );
@@ -65,7 +65,7 @@
 	/* translators: add new file */
 	$submenu['upload.php'][10] = array( _x('Add New', 'file'), 'upload_files', 'media-new.php');
 	foreach ( get_taxonomies_for_attachments( 'objects' ) as $tax ) {
-		if ( ! $tax->show_ui )
+		if ( ! $tax->show_ui || ! $tax->show_in_menu )
 			continue;
 
 		$submenu['upload.php'][$i++] = array( esc_attr( $tax->labels->menu_name ), $tax->cap->manage_terms, 'edit-tags.php?taxonomy=' . $tax->name . '&post_type=attachment' );
@@ -84,7 +84,7 @@
 	$submenu['edit.php?post_type=page'][10] = array( _x('Add New', 'page'), get_post_type_object( 'page' )->cap->create_posts, 'post-new.php?post_type=page' );
 	$i = 15;
 	foreach ( get_taxonomies( array(), 'objects' ) as $tax ) {
-		if ( ! $tax->show_ui || ! in_array('page', (array) $tax->object_type, true) )
+		if ( ! $tax->show_ui || ! $tax->show_in_menu  || ! in_array('page', (array) $tax->object_type, true) )
 			continue;
 
 		$submenu['edit.php?post_type=page'][$i++] = array( esc_attr( $tax->labels->menu_name ), $tax->cap->manage_terms, 'edit-tags.php?taxonomy=' . $tax->name . '&post_type=page' );
Index: src/wp-includes/class-wp-xmlrpc-server.php
===================================================================
--- src/wp-includes/class-wp-xmlrpc-server.php	(revision 25130)
+++ src/wp-includes/class-wp-xmlrpc-server.php	(working copy)
@@ -547,6 +547,9 @@
 		if ( in_array( 'cap', $fields ) )
 			$_taxonomy['cap'] = (array) $taxonomy->cap;
 
+		if ( in_array( 'menu', $fields ) )
+			$_taxonomy['show_in_menu'] = (bool) $_taxonomy->show_in_menu;
+
 		if ( in_array( 'object_type', $fields ) )
 			$_taxonomy['object_type'] = array_unique( (array) $taxonomy->object_type );
 
Index: src/wp-includes/taxonomy.php
===================================================================
--- src/wp-includes/taxonomy.php	(revision 25130)
+++ src/wp-includes/taxonomy.php	(working copy)
@@ -280,6 +280,11 @@
  * - hierarchical - Whether the taxonomy is hierarchical (e.g. category). Defaults to false.
  * - show_ui -Whether to generate a default UI for managing this taxonomy in the admin.
  *     * If not set, the default is inherited from public.
+ * - show_in_menu - Where to show the taxonomy in the admin menu.
+ *     * If true, the taxonomy is shown as a submenu of the object type menu.
+ *     * If false, no menu is shown.
+ *     * show_ui must be true.
+ *     * If not set, the default is inherited from show_ui.
  * - show_in_nav_menus - Makes this taxonomy available for selection in navigation menus.
  *     * If not set, the default is inherited from public.
  * - show_tagcloud - Whether to list the taxonomy in the Tag Cloud Widget.
@@ -324,6 +329,7 @@
 		'public'                => true,
 		'hierarchical'          => false,
 		'show_ui'               => null,
+		'show_in_menu'          => null,
 		'show_in_nav_menus'     => null,
 		'show_tagcloud'         => null,
 		'capabilities'          => array(),
@@ -366,6 +372,10 @@
 	if ( null === $args['show_ui'] )
 		$args['show_ui'] = $args['public'];
 
+	// If not set, default to the setting for show_ui.
+	if ( null === $args['show_in_menu' ] || ! $args['show_ui'] )
+		$args['show_in_menu' ] = $args['show_ui'];
+
 	// If not set, default to the setting for public.
 	if ( null === $args['show_in_nav_menus'] )
 		$args['show_in_nav_menus'] = $args['public'];