Index: src/wp-admin/custom-background.php
===================================================================
--- src/wp-admin/custom-background.php	(revision 34551)
+++ src/wp-admin/custom-background.php	(working copy)
@@ -18,7 +18,7 @@
 	/**
 	 * Callback for administration header.
 	 *
-	 * @var callback
+	 * @var callable
 	 * @since 3.0.0
 	 */
 	public $admin_header_callback;
@@ -26,7 +26,7 @@
 	/**
 	 * Callback for header div.
 	 *
-	 * @var callback
+	 * @var callable
 	 * @since 3.0.0
 	 */
 	public $admin_image_div_callback;
@@ -44,8 +44,8 @@
 	 * Constructor - Register administration header callback.
 	 *
 	 * @since 3.0.0
-	 * @param callback $admin_header_callback
-	 * @param callback $admin_image_div_callback Optional custom image div output callback.
+	 * @param callable $admin_header_callback
+	 * @param callable $admin_image_div_callback Optional custom image div output callback.
 	 */
 	public function __construct($admin_header_callback = '', $admin_image_div_callback = '') {
 		$this->admin_header_callback = $admin_header_callback;
Index: src/wp-admin/custom-header.php
===================================================================
--- src/wp-admin/custom-header.php	(revision 34551)
+++ src/wp-admin/custom-header.php	(working copy)
@@ -18,7 +18,7 @@
 	/**
 	 * Callback for administration header.
 	 *
-	 * @var callback
+	 * @var callable
 	 * @since 2.1.0
 	 */
 	public $admin_header_callback;
@@ -26,7 +26,7 @@
 	/**
 	 * Callback for header div.
 	 *
-	 * @var callback
+	 * @var callable
 	 * @since 3.0.0
 	 */
 	public $admin_image_div_callback;
@@ -53,8 +53,8 @@
 	 * Constructor - Register administration header callback.
 	 *
 	 * @since 2.1.0
-	 * @param callback $admin_header_callback
-	 * @param callback $admin_image_div_callback Optional custom image div output callback.
+	 * @param callable $admin_header_callback
+	 * @param callable $admin_image_div_callback Optional custom image div output callback.
 	 */
 	public function __construct($admin_header_callback, $admin_image_div_callback = '') {
 		$this->admin_header_callback = $admin_header_callback;
Index: src/wp-admin/includes/class-wp-upgrader.php
===================================================================
--- src/wp-admin/includes/class-wp-upgrader.php	(revision 34551)
+++ src/wp-admin/includes/class-wp-upgrader.php	(working copy)
@@ -2147,7 +2147,7 @@
 	 * @access public
 	 *
 	 * @global WP_Filesystem_Base $wp_filesystem Subclass
-	 * @global callback           $_wp_filesystem_direct_method
+	 * @global callable           $_wp_filesystem_direct_method
 	 *
 	 * @param object $current Response object for whether WordPress is current.
 	 * @param array  $args {
Index: src/wp-admin/includes/dashboard.php
===================================================================
--- src/wp-admin/includes/dashboard.php	(revision 34551)
+++ src/wp-admin/includes/dashboard.php	(working copy)
@@ -135,8 +135,8 @@
  *
  * @param string   $widget_id
  * @param string   $widget_name
- * @param callback $callback
- * @param callback $control_callback
+ * @param callable $callback
+ * @param callable $control_callback
  * @param array    $callback_args
  */
 function wp_add_dashboard_widget( $widget_id, $widget_name, $callback, $control_callback = null, $callback_args = null ) {
@@ -886,7 +886,7 @@
  * @since 2.5.0
  *
  * @param string $widget_id
- * @param callback $callback
+ * @param callable $callback
  * @param array $check_urls RSS feeds
  * @return bool False on failure. True on success.
  */
Index: src/wp-admin/includes/file.php
===================================================================
--- src/wp-admin/includes/file.php	(revision 34551)
+++ src/wp-admin/includes/file.php	(working copy)
@@ -909,7 +909,7 @@
  *
  * @since 2.5.0
  *
- * @global callback $_wp_filesystem_direct_method
+ * @global callable $_wp_filesystem_direct_method
  *
  * @param array  $args                         Optional. Connection details. Default empty array.
  * @param string $context                      Optional. Full path to the directory that is tested
Index: src/wp-admin/includes/import.php
===================================================================
--- src/wp-admin/includes/import.php	(revision 34551)
+++ src/wp-admin/includes/import.php	(working copy)
@@ -48,7 +48,7 @@
  * @param string   $id          Importer tag. Used to uniquely identify importer.
  * @param string   $name        Importer name and title.
  * @param string   $description Importer description.
- * @param callback $callback    Callback to run.
+ * @param callable $callback    Callback to run.
  * @return WP_Error Returns WP_Error when $callback is WP_Error.
  */
 function register_importer( $id, $name, $description, $callback ) {
Index: src/wp-admin/includes/meta-boxes.php
===================================================================
--- src/wp-admin/includes/meta-boxes.php	(revision 34551)
+++ src/wp-admin/includes/meta-boxes.php	(working copy)
@@ -345,7 +345,7 @@
  *
  *     @type string   $id       Meta box ID.
  *     @type string   $title    Meta box title.
- *     @type callback $callback Meta box display callback.
+ *     @type callable $callback Meta box display callback.
  *     @type array    $args     Extra meta box arguments.
  * }
  */
@@ -386,7 +386,7 @@
  *
  *     @type string   $id       Meta box ID.
  *     @type string   $title    Meta box title.
- *     @type callback $callback Meta box display callback.
+ *     @type callable $callback Meta box display callback.
  *     @type array    $args {
  *         Extra meta box arguments.
  *
@@ -442,7 +442,7 @@
  *
  *     @type string   $id       Meta box ID.
  *     @type string   $title    Meta box title.
- *     @type callback $callback Meta box display callback.
+ *     @type callable $callback Meta box display callback.
  *     @type array    $args {
  *         Extra meta box arguments.
  *
Index: src/wp-admin/includes/plugin.php
===================================================================
--- src/wp-admin/includes/plugin.php	(revision 34551)
+++ src/wp-admin/includes/plugin.php	(working copy)
@@ -1014,7 +1014,7 @@
  * @param string $menu_title The text to be used for the menu
  * @param string $capability The capability required for this menu to be displayed to the user.
  * @param string $menu_slug The slug name to refer to this menu by (should be unique for this menu)
- * @param callback $function The function to be called to output the content for this page.
+ * @param callable $function The function to be called to output the content for this page.
  * @param string $icon_url The url to the icon to be used for this menu.
  *     * Pass a base64-encoded SVG using a data URI, which will be colored to match the color scheme.
  *       This should begin with 'data:image/svg+xml;base64,'.
@@ -1074,7 +1074,7 @@
  * @param string $menu_title The text to be used for the menu
  * @param string $capability The capability required for this menu to be displayed to the user.
  * @param string $menu_slug The slug name to refer to this menu by (should be unique for this menu)
- * @param callback $function The function to be called to output the content for this page.
+ * @param callable $function The function to be called to output the content for this page.
  * @param string $icon_url The url to the icon to be used for this menu
  *
  * @return string The resulting page's hook_suffix
@@ -1102,7 +1102,7 @@
  * @param string $menu_title The text to be used for the menu
  * @param string $capability The capability required for this menu to be displayed to the user.
  * @param string $menu_slug The slug name to refer to this menu by (should be unique for this menu)
- * @param callback $function The function to be called to output the content for this page.
+ * @param callable $function The function to be called to output the content for this page.
  * @param string $icon_url The url to the icon to be used for this menu
  *
  * @return string The resulting page's hook_suffix
@@ -1136,7 +1136,7 @@
  * @param string $menu_title The text to be used for the menu
  * @param string $capability The capability required for this menu to be displayed to the user.
  * @param string $menu_slug The slug name to refer to this menu by (should be unique for this menu)
- * @param callback $function The function to be called to output the content for this page.
+ * @param callable $function The function to be called to output the content for this page.
  *
  * @return false|string The resulting page's hook_suffix, or false if the user does not have the capability required.
  */
@@ -1202,7 +1202,7 @@
  * @param string $menu_title The text to be used for the menu
  * @param string $capability The capability required for this menu to be displayed to the user.
  * @param string $menu_slug The slug name to refer to this menu by (should be unique for this menu)
- * @param callback $function The function to be called to output the content for this page.
+ * @param callable $function The function to be called to output the content for this page.
  *
  * @return false|string The resulting page's hook_suffix, or false if the user does not have the capability required.
  */
@@ -1223,7 +1223,7 @@
  * @param string $menu_title The text to be used for the menu
  * @param string $capability The capability required for this menu to be displayed to the user.
  * @param string $menu_slug The slug name to refer to this menu by (should be unique for this menu)
- * @param callback $function The function to be called to output the content for this page.
+ * @param callable $function The function to be called to output the content for this page.
  *
  * @return false|string The resulting page's hook_suffix, or false if the user does not have the capability required.
  */
@@ -1244,7 +1244,7 @@
  * @param string $menu_title The text to be used for the menu
  * @param string $capability The capability required for this menu to be displayed to the user.
  * @param string $menu_slug The slug name to refer to this menu by (should be unique for this menu)
- * @param callback $function The function to be called to output the content for this page.
+ * @param callable $function The function to be called to output the content for this page.
  *
  * @return false|string The resulting page's hook_suffix, or false if the user does not have the capability required.
  */
@@ -1265,7 +1265,7 @@
  * @param string $menu_title The text to be used for the menu
  * @param string $capability The capability required for this menu to be displayed to the user.
  * @param string $menu_slug The slug name to refer to this menu by (should be unique for this menu)
- * @param callback $function The function to be called to output the content for this page.
+ * @param callable $function The function to be called to output the content for this page.
  *
  * @return false|string The resulting page's hook_suffix, or false if the user does not have the capability required.
  */
@@ -1286,7 +1286,7 @@
  * @param string $menu_title The text to be used for the menu
  * @param string $capability The capability required for this menu to be displayed to the user.
  * @param string $menu_slug The slug name to refer to this menu by (should be unique for this menu)
- * @param callback $function The function to be called to output the content for this page.
+ * @param callable $function The function to be called to output the content for this page.
  *
  * @return false|string The resulting page's hook_suffix, or false if the user does not have the capability required.
  */
@@ -1310,7 +1310,7 @@
  * @param string $menu_title The text to be used for the menu
  * @param string $capability The capability required for this menu to be displayed to the user.
  * @param string $menu_slug The slug name to refer to this menu by (should be unique for this menu)
- * @param callback $function The function to be called to output the content for this page.
+ * @param callable $function The function to be called to output the content for this page.
  *
  * @return false|string The resulting page's hook_suffix, or false if the user does not have the capability required.
  */
@@ -1331,7 +1331,7 @@
  * @param string $menu_title The text to be used for the menu
  * @param string $capability The capability required for this menu to be displayed to the user.
  * @param string $menu_slug The slug name to refer to this menu by (should be unique for this menu)
- * @param callback $function The function to be called to output the content for this page.
+ * @param callable $function The function to be called to output the content for this page.
  *
  * @return false|string The resulting page's hook_suffix, or false if the user does not have the capability required.
  */
@@ -1352,7 +1352,7 @@
  * @param string $menu_title The text to be used for the menu
  * @param string $capability The capability required for this menu to be displayed to the user.
  * @param string $menu_slug The slug name to refer to this menu by (should be unique for this menu)
- * @param callback $function The function to be called to output the content for this page.
+ * @param callable $function The function to be called to output the content for this page.
  *
  * @return false|string The resulting page's hook_suffix, or false if the user does not have the capability required.
  */
@@ -1373,7 +1373,7 @@
  * @param string $menu_title The text to be used for the menu
  * @param string $capability The capability required for this menu to be displayed to the user.
  * @param string $menu_slug The slug name to refer to this menu by (should be unique for this menu)
- * @param callback $function The function to be called to output the content for this page.
+ * @param callable $function The function to be called to output the content for this page.
  *
  * @return false|string The resulting page's hook_suffix, or false if the user does not have the capability required.
  */
@@ -1394,7 +1394,7 @@
  * @param string $menu_title The text to be used for the menu
  * @param string $capability The capability required for this menu to be displayed to the user.
  * @param string $menu_slug The slug name to refer to this menu by (should be unique for this menu)
- * @param callback $function The function to be called to output the content for this page.
+ * @param callable $function The function to be called to output the content for this page.
  *
  * @return false|string The resulting page's hook_suffix, or false if the user does not have the capability required.
 */
@@ -1415,7 +1415,7 @@
  * @param string $menu_title The text to be used for the menu
  * @param string $capability The capability required for this menu to be displayed to the user.
  * @param string $menu_slug The slug name to refer to this menu by (should be unique for this menu)
- * @param callback $function The function to be called to output the content for this page.
+ * @param callable $function The function to be called to output the content for this page.
  *
  * @return false|string The resulting page's hook_suffix, or false if the user does not have the capability required.
 */
Index: src/wp-admin/includes/template-functions.php
===================================================================
--- src/wp-admin/includes/template-functions.php	(revision 34551)
+++ src/wp-admin/includes/template-functions.php	(working copy)
@@ -850,7 +850,7 @@
  *
  * @param string           $id            String for use in the 'id' attribute of tags.
  * @param string           $title         Title of the meta box.
- * @param callback         $callback      Function that fills the box with the desired content.
+ * @param callable         $callback      Function that fills the box with the desired content.
  *                                        The function should echo its output.
  * @param string|WP_Screen $screen        Optional. The screen on which to show the box (like a post
  *                                        type, 'link', or 'comment'). Default is the current screen.
Index: src/wp-includes/SimplePie/Parse/Date.php
===================================================================
--- src/wp-includes/SimplePie/Parse/Date.php	(revision 34551)
+++ src/wp-includes/SimplePie/Parse/Date.php	(working copy)
@@ -613,7 +613,7 @@
 	 *
 	 * @final
 	 * @access public
-	 * @param callback $callback
+	 * @param callable $callback
 	 */
 	public function add_callback($callback)
 	{
Index: src/wp-includes/deprecated.php
===================================================================
--- src/wp-includes/deprecated.php	(revision 34551)
+++ src/wp-includes/deprecated.php	(working copy)
@@ -2080,7 +2080,7 @@
  * @see wp_register_sidebar_widget()
  *
  * @param string|int $name Widget ID.
- * @param callback $output_callback Run when widget is called.
+ * @param callable $output_callback Run when widget is called.
  * @param string $classname Classname widget option.
  * @param mixed $params ,... Widget parameters.
  */
@@ -2135,7 +2135,7 @@
  * @see wp_register_widget_control()
  *
  * @param int|string $name Sidebar ID.
- * @param callback $control_callback Widget control callback to display and process form.
+ * @param callable $control_callback Widget control callback to display and process form.
  * @param int $width Widget width.
  * @param int $height Widget height.
  */
@@ -2928,9 +2928,9 @@
  * @deprecated 3.4.0 Use add_theme_support()
  * @see add_theme_support()
  *
- * @param callback $wp_head_callback Call on 'wp_head' action.
- * @param callback $admin_head_callback Call on custom header administration screen.
- * @param callback $admin_preview_callback Output a custom header image div on the custom header administration screen. Optional.
+ * @param callable $wp_head_callback Call on 'wp_head' action.
+ * @param callable $admin_head_callback Call on custom header administration screen.
+ * @param callable $admin_preview_callback Output a custom header image div on the custom header administration screen. Optional.
  */
 function add_custom_image_header( $wp_head_callback, $admin_head_callback, $admin_preview_callback = '' ) {
 	_deprecated_function( __FUNCTION__, '3.4', 'add_theme_support( \'custom-header\', $args )' );
@@ -2964,9 +2964,9 @@
  * @deprecated 3.4.0 Use add_theme_support()
  * @see add_theme_support()
  *
- * @param callback $wp_head_callback Call on 'wp_head' action.
- * @param callback $admin_head_callback Call on custom background administration screen.
- * @param callback $admin_preview_callback Output a custom background image div on the custom background administration screen. Optional.
+ * @param callable $wp_head_callback Call on 'wp_head' action.
+ * @param callable $admin_head_callback Call on custom background administration screen.
+ * @param callable $admin_preview_callback Output a custom background image div on the custom background administration screen. Optional.
  */
 function add_custom_background( $wp_head_callback = '', $admin_head_callback = '', $admin_preview_callback = '' ) {
 	_deprecated_function( __FUNCTION__, '3.4', 'add_theme_support( \'custom-background\', $args )' );
Index: src/wp-includes/functions.php
===================================================================
--- src/wp-includes/functions.php	(revision 34551)
+++ src/wp-includes/functions.php	(working copy)
@@ -1873,7 +1873,7 @@
  *
  * @param string   $dir                      Directory.
  * @param string   $filename                 File name.
- * @param callback $unique_filename_callback Callback. Default null.
+ * @param callable $unique_filename_callback Callback. Default null.
  * @return string New filename, if given wasn't unique.
  */
 function wp_unique_filename( $dir, $filename, $unique_filename_callback = null ) {
@@ -2395,7 +2395,7 @@
 		 *
 		 * @since 3.4.0
 		 *
-		 * @param callback $function Callback function name.
+		 * @param callable $function Callback function name.
 		 */
 		$function = apply_filters( 'wp_die_ajax_handler', '_ajax_wp_die_handler' );
 	} elseif ( defined( 'XMLRPC_REQUEST' ) && XMLRPC_REQUEST ) {
@@ -2404,7 +2404,7 @@
 		 *
 		 * @since 3.4.0
 		 *
-		 * @param callback $function Callback function name.
+		 * @param callable $function Callback function name.
 		 */
 		$function = apply_filters( 'wp_die_xmlrpc_handler', '_xmlrpc_wp_die_handler' );
 	} else {
@@ -2413,7 +2413,7 @@
 		 *
 		 * @since 3.0.0
 		 *
-		 * @param callback $function Callback function name.
+		 * @param callable $function Callback function name.
 		 */
 		$function = apply_filters( 'wp_die_handler', '_default_wp_die_handler' );
 	}
@@ -4475,7 +4475,7 @@
  * @since 3.1.0
  * @access private
  *
- * @param callback $callback      Function that accepts ( ID, $callback_args ) and outputs parent_ID.
+ * @param callable $callback      Function that accepts ( ID, $callback_args ) and outputs parent_ID.
  * @param int      $start         The ID to start the loop check at.
  * @param int      $start_parent  The parent_ID of $start to use instead of calling $callback( $start ).
  *                                Use null to always use $callback
@@ -4500,7 +4500,7 @@
  * @since 3.1.0
  * @access private
  *
- * @param callback $callback      Function that accepts ( ID, callback_arg, ... ) and outputs parent_ID.
+ * @param callable $callback      Function that accepts ( ID, callback_arg, ... ) and outputs parent_ID.
  * @param int      $start         The ID to start the loop check at.
  * @param array    $override      Optional. An array of ( ID => parent_ID, ... ) to use instead of $callback.
  *                                Default empty array.
Index: src/wp-includes/media.php
===================================================================
--- src/wp-includes/media.php	(revision 34551)
+++ src/wp-includes/media.php	(working copy)
@@ -2187,7 +2187,7 @@
  *
  * @param string   $id       An internal ID/name for the handler. Needs to be unique.
  * @param string   $regex    The regex that will be used to see if this handler should be used for a URL.
- * @param callback $callback The callback function that will be called if the regex is matched.
+ * @param callable $callback The callback function that will be called if the regex is matched.
  * @param int      $priority Optional. Used to specify the order in which the registered handlers will
  *                           be tested. Default 10.
  */
@@ -2373,7 +2373,7 @@
 	 *
 	 * @since 3.6.0
 	 *
-	 * @param callback $handler Audio embed handler callback function.
+	 * @param callable $handler Audio embed handler callback function.
 	 */
 	wp_embed_register_handler( 'audio', '#^https?://.+?\.(' . join( '|', wp_get_audio_extensions() ) . ')$#i', apply_filters( 'wp_audio_embed_handler', 'wp_embed_handler_audio' ), 9999 );
 
@@ -2382,7 +2382,7 @@
 	 *
 	 * @since 3.6.0
 	 *
-	 * @param callback $handler Video embed handler callback function.
+	 * @param callable $handler Video embed handler callback function.
 	 */
 	wp_embed_register_handler( 'video', '#^https?://.+?\.(' . join( '|', wp_get_video_extensions() ) . ')$#i', apply_filters( 'wp_video_embed_handler', 'wp_embed_handler_video' ), 9999 );
 }
Index: src/wp-includes/nav-menu-template.php
===================================================================
--- src/wp-includes/nav-menu-template.php	(revision 34551)
+++ src/wp-includes/nav-menu-template.php	(working copy)
@@ -219,7 +219,7 @@
  *     @type string        $container       Whether to wrap the ul, and what to wrap it with. Default 'div'.
  *     @type string        $container_class Class that is applied to the container. Default 'menu-{menu slug}-container'.
  *     @type string        $container_id    The ID that is applied to the container. Default empty.
- *     @type callback|bool $fallback_cb     If the menu doesn't exists, a callback function will fire.
+ *     @type callable|bool $fallback_cb     If the menu doesn't exists, a callback function will fire.
  *                                          Default is 'wp_page_menu'. Set to false for no fallback.
  *     @type string        $before          Text before the link text. Default empty.
  *     @type string        $after           Text after the link text. Default empty.
Index: src/wp-includes/plugin.php
===================================================================
--- src/wp-includes/plugin.php	(revision 34551)
+++ src/wp-includes/plugin.php	(working copy)
@@ -91,7 +91,7 @@
  *                               it doesn't need to run through that process.
  *
  * @param string   $tag             The name of the filter to hook the $function_to_add callback to.
- * @param callback $function_to_add The callback to be run when the filter is applied.
+ * @param callable $function_to_add The callback to be run when the filter is applied.
  * @param int      $priority        Optional. Used to specify the order in which the functions
  *                                  associated with a particular action are executed. Default 10.
  *                                  Lower numbers correspond with earlier execution,
@@ -117,7 +117,7 @@
  * @global array $wp_filter Stores all of the filters.
  *
  * @param string        $tag               The name of the filter hook.
- * @param callback|bool $function_to_check Optional. The callback to check for. Default false.
+ * @param callable|bool $function_to_check Optional. The callback to check for. Default false.
  * @return false|int If $function_to_check is omitted, returns boolean for whether the hook has
  *                   anything registered. When checking a specific function, the priority of that
  *                   hook is returned, or false if the function is not attached. When using the
@@ -314,7 +314,7 @@
  * @global array $merged_filters    Merges the filter hooks using this function.
  *
  * @param string   $tag                The filter hook to which the function to be removed is hooked.
- * @param callback $function_to_remove The name of the function which should be removed.
+ * @param callable $function_to_remove The name of the function which should be removed.
  * @param int      $priority           Optional. The priority of the function. Default 10.
  * @return bool    Whether the function existed before it was removed.
  */
@@ -445,7 +445,7 @@
  * @since 1.2.0
  *
  * @param string   $tag             The name of the action to which the $function_to_add is hooked.
- * @param callback $function_to_add The name of the function you wish to be called.
+ * @param callable $function_to_add The name of the function you wish to be called.
  * @param int      $priority        Optional. Used to specify the order in which the functions
  *                                  associated with a particular action are executed. Default 10.
  *                                  Lower numbers correspond with earlier execution,
@@ -613,7 +613,7 @@
  * @see has_filter() has_action() is an alias of has_filter().
  *
  * @param string        $tag               The name of the action hook.
- * @param callback|bool $function_to_check Optional. The callback to check for. Default false.
+ * @param callable|bool $function_to_check Optional. The callback to check for. Default false.
  * @return bool|int If $function_to_check is omitted, returns boolean for whether the hook has
  *                  anything registered. When checking a specific function, the priority of that
  *                  hook is returned, or false if the function is not attached. When using the
@@ -635,7 +635,7 @@
  * @since 1.2.0
  *
  * @param string   $tag                The action hook to which the function to be removed is hooked.
- * @param callback $function_to_remove The name of the function which should be removed.
+ * @param callable $function_to_remove The name of the function which should be removed.
  * @param int      $priority           Optional. The priority of the function. Default 10.
  * @return bool Whether the function is removed.
  */
@@ -771,7 +771,7 @@
  * @since 2.0.0
  *
  * @param string   $file     The filename of the plugin including the path.
- * @param callback $function The function hooked to the 'activate_PLUGIN' action.
+ * @param callable $function The function hooked to the 'activate_PLUGIN' action.
  */
 function register_activation_hook($file, $function) {
 	$file = plugin_basename($file);
@@ -794,7 +794,7 @@
  * @since 2.0.0
  *
  * @param string   $file     The filename of the plugin including the path.
- * @param callback $function The function hooked to the 'deactivate_PLUGIN' action.
+ * @param callable $function The function hooked to the 'deactivate_PLUGIN' action.
  */
 function register_deactivation_hook($file, $function) {
 	$file = plugin_basename($file);
@@ -824,7 +824,7 @@
  * @since 2.7.0
  *
  * @param string   $file     Plugin file.
- * @param callback $callback The callback to run when the hook is called. Must be
+ * @param callable $callback The callback to run when the hook is called. Must be
  *                           a static method or function.
  */
 function register_uninstall_hook( $file, $callback ) {
@@ -900,7 +900,7 @@
  * @staticvar int $filter_id_count
  *
  * @param string   $tag      Used in counting how many hooks were applied
- * @param callback $function Used for creating unique id
+ * @param callable $function Used for creating unique id
  * @param int|bool $priority Used in counting how many hooks were applied. If === false
  *                           and $function is an object reference, we return the unique
  *                           id only if it already has one, false otherwise.
Index: src/wp-includes/post-functions.php
===================================================================
--- src/wp-includes/post-functions.php	(revision 34551)
+++ src/wp-includes/post-functions.php	(working copy)
@@ -940,7 +940,7 @@
  *                                             Default false.
  *     @type array       $supports             An alias for calling {@see add_post_type_support()} directly.
  *                                             Defaults to array containing 'title' & 'editor'.
- *     @type callback    $register_meta_box_cb Provide a callback function that sets up the meta boxes for the
+ *     @type callable    $register_meta_box_cb Provide a callback function that sets up the meta boxes for the
  *                                             edit form. Do remove_meta_box() and add_meta_box() calls in the
  *                                             callback. Default null.
  *     @type array       $taxonomies           An array of taxonomy identifiers that will be registered for the
Index: src/wp-includes/rewrite-functions.php
===================================================================
--- src/wp-includes/rewrite-functions.php	(revision 34551)
+++ src/wp-includes/rewrite-functions.php	(working copy)
@@ -86,7 +86,7 @@
  * @global WP_Rewrite $wp_rewrite
  *
  * @param string   $feedname
- * @param callback $function Callback to run on feed display.
+ * @param callable $function Callback to run on feed display.
  * @return string Feed action name.
  */
 function add_feed($feedname, $function) {
Index: src/wp-includes/widget-functions.php
===================================================================
--- src/wp-includes/widget-functions.php	(revision 34551)
+++ src/wp-includes/widget-functions.php	(working copy)
@@ -222,7 +222,7 @@
  *
  * @param int|string $id              Widget ID.
  * @param string     $name            Widget display title.
- * @param callback   $output_callback Run when widget is called.
+ * @param callable   $output_callback Run when widget is called.
  * @param array      $options {
  *     Optional. An array of supplementary widget options for the instance.
  *
@@ -364,7 +364,7 @@
  *
  * @param int|string   $id               Sidebar ID.
  * @param string       $name             Sidebar display name.
- * @param callback     $control_callback Run when sidebar is displayed.
+ * @param callable     $control_callback Run when sidebar is displayed.
  * @param array|string $options          Optional. Widget options. See description above. Default empty array.
  */
 function wp_register_widget_control( $id, $name, $control_callback, $options = array() ) {
@@ -613,7 +613,7 @@
 		 *
 		 *     @type string $name                Name of the widget.
 		 *     @type string $id                  Widget ID.
-		 *     @type array|callback $callback    When the hook is fired on the front-end, $callback is an array
+		 *     @type array|callable $callback    When the hook is fired on the front-end, $callback is an array
 		 *                                       containing the widget object. Fired on the back-end, $callback
 		 *                                       is 'wp_widget_control', see $_callback.
 		 *     @type array          $params      An associative array of multi-widget arguments.
Index: src/wp-includes/widgets/class-wp-nav-menu-widget.php
===================================================================
--- src/wp-includes/widgets/class-wp-nav-menu-widget.php	(revision 34551)
+++ src/wp-includes/widgets/class-wp-nav-menu-widget.php	(working copy)
@@ -53,7 +53,7 @@
 		 * @param array    $nav_menu_args {
 		 *     An array of arguments passed to wp_nav_menu() to retrieve a custom menu.
 		 *
-		 *     @type callback|bool $fallback_cb Callback to fire if the menu doesn't exist. Default empty.
+		 *     @type callable|bool $fallback_cb Callback to fire if the menu doesn't exist. Default empty.
 		 *     @type mixed         $menu        Menu ID, slug, or name.
 		 * }
 		 * @param stdClass $nav_menu      Nav menu object for the current menu.