diff --git a/src/wp-includes/ms-blogs.php b/src/wp-includes/ms-blogs.php
index 74885b1350..966fb73f1d 100644
--- a/src/wp-includes/ms-blogs.php
+++ b/src/wp-includes/ms-blogs.php
@@ -12,6 +12,8 @@
  * Update the last_updated field for the current blog.
  *
  * @since MU
+ *
+ * @global wpdb $wpdb
  */
 function wpmu_update_blogs_date() {
 	global $wpdb;
@@ -66,6 +68,8 @@ function get_blogaddress_by_name( $blogname ) {
  *
  * @since MU
  *
+ * @global wpdb $wpdb
+ *
  * @param string $slug
  * @return int A blog id
  */
@@ -97,8 +101,12 @@ function get_id_from_blogname( $slug ) {
  *
  * @since MU
  *
- * @param int|string|array $fields A blog ID, a blog slug, or an array of fields to query against. Optional. If not specified the current blog ID is used.
- * @param bool $get_all Whether to retrieve all details or only the details in the blogs table. Default is true.
+ * @global wpdb $wpdb
+ *
+ * @param int|string|array $fields  Optional. A blog ID, a blog slug, or an array of fields to query against.
+ *                                  If not specified the current blog ID is used.
+ * @param bool             $get_all Whether to retrieve all details or only the details in the blogs table.
+ *                                  Default is true.
  * @return object|false Blog details on success. False on failure.
  */
 function get_blog_details( $fields = null, $get_all = true ) {
@@ -272,7 +280,9 @@ function refresh_blog_details( $blog_id = 0 ) {
  *
  * @since MU
  *
- * @param int $blog_id Blog ID
+ * @global wpdb $wpdb
+ *
+ * @param int   $blog_id Blog ID
  * @param array $details Array of details keyed by blogs table field names.
  * @return bool True if update succeeds, false otherwise.
  */
@@ -444,9 +454,9 @@ function clean_blog_cache( $blog ) {
  *
  * @since MU
  *
- * @param int $id A blog ID. Can be null to refer to the current blog.
- * @param string $option Name of option to retrieve. Expected to not be SQL-escaped.
- * @param mixed $default Optional. Default value to return if the option does not exist.
+ * @param int    $id      A blog ID. Can be null to refer to the current blog.
+ * @param string $option  Name of option to retrieve. Expected to not be SQL-escaped.
+ * @param mixed  $default Optional. Default value to return if the option does not exist.
  * @return mixed Value set for the option.
  */
 function get_blog_option( $id, $option, $default = false ) {
@@ -489,9 +499,9 @@ function get_blog_option( $id, $option, $default = false ) {
  *
  * @since MU
  *
- * @param int $id A blog ID. Can be null to refer to the current blog.
+ * @param int    $id     A blog ID. Can be null to refer to the current blog.
  * @param string $option Name of option to add. Expected to not be SQL-escaped.
- * @param mixed $value Optional. Option value, can be anything. Expected to not be SQL-escaped.
+ * @param mixed  $value  Optional. Option value, can be anything. Expected to not be SQL-escaped.
  * @return bool False if option was not added and true if option was added.
  */
 function add_blog_option( $id, $option, $value ) {
@@ -515,7 +525,7 @@ function add_blog_option( $id, $option, $value ) {
  *
  * @since MU
  *
- * @param int $id A blog ID. Can be null to refer to the current blog.
+ * @param int    $id     A blog ID. Can be null to refer to the current blog.
  * @param string $option Name of option to remove. Expected to not be SQL-escaped.
  * @return bool True, if option is successfully deleted. False on failure.
  */
@@ -540,9 +550,9 @@ function delete_blog_option( $id, $option ) {
  *
  * @since MU
  *
- * @param int $id The blog id
+ * @param int    $id     The blog id
  * @param string $option The option key
- * @param mixed $value The option value
+ * @param mixed  $value  The option value
  * @return bool True on success, false on failure.
  */
 function update_blog_option( $id, $option, $value, $deprecated = null ) {
@@ -576,12 +586,19 @@ function update_blog_option( $id, $option, $value, $deprecated = null ) {
  * @see restore_current_blog()
  * @since MU
  *
- * @param int $new_blog The id of the blog you want to switch to. Default: current blog
+ * @global wpdb            $wpdb
+ * @global int             $blog_id
+ * @global array           $_wp_switched_stack
+ * @global bool            $switched
+ * @global string          $table_prefix
+ * @global WP_Object_Cache $wp_object_cache
+ *
+ * @param int  $new_blog   The id of the blog you want to switch to. Default: current blog
  * @param bool $deprecated Deprecated argument
- * @return bool Always returns True.
+ * @return true Always returns True.
  */
 function switch_to_blog( $new_blog, $deprecated = null ) {
-	global $wpdb, $wp_roles;
+	global $wpdb;
 
 	if ( empty( $new_blog ) )
 		$new_blog = $GLOBALS['blog_id'];
@@ -635,7 +652,7 @@ function switch_to_blog( $new_blog, $deprecated = null ) {
 	}
 
 	if ( did_action( 'init' ) ) {
-		$wp_roles->reinit();
+		wp_roles()->reinit();
 		$current_user = wp_get_current_user();
 		$current_user->for_blog( $new_blog );
 	}
@@ -653,10 +670,17 @@ function switch_to_blog( $new_blog, $deprecated = null ) {
  * @see switch_to_blog()
  * @since MU
  *
+ * @global wpdb            $wpdb
+ * @global array           $_wp_switched_stack
+ * @global int             $blog_id
+ * @global bool            $switched
+ * @global string          $table_prefix
+ * @global WP_Object_Cache $wp_object_cache
+ *
  * @return bool True on success, false if we're already on the current blog
  */
 function restore_current_blog() {
-	global $wpdb, $wp_roles;
+	global $wpdb;
 
 	if ( empty( $GLOBALS['_wp_switched_stack'] ) )
 		return false;
@@ -699,7 +723,7 @@ function restore_current_blog() {
 	}
 
 	if ( did_action( 'init' ) ) {
-		$wp_roles->reinit();
+		wp_roles()->reinit();
 		$current_user = wp_get_current_user();
 		$current_user->for_blog( $blog );
 	}
@@ -718,6 +742,8 @@ function restore_current_blog() {
  *
  * @since 3.5.0
  *
+ * @global array $_wp_switched_stack
+ *
  * @return bool True if switched, false otherwise.
  */
 function ms_is_switched() {
@@ -741,7 +767,7 @@ function is_archived( $id ) {
  *
  * @since MU
  *
- * @param int $id The blog id
+ * @param int    $id       The blog id
  * @param string $archived The new status
  * @return string $archived
  */
@@ -755,10 +781,13 @@ function update_archived( $id, $archived ) {
  *
  * @since MU
  *
- * @param int $blog_id BLog ID
- * @param string $pref A field name
- * @param string $value Value for $pref
- * @return string $value
+ * @global wpdb $wpdb
+ *
+ * @param int    $blog_id BLog ID
+ * @param string $pref    A field name
+ * @param string $value   Value for $pref
+ * @param null   $deprecated
+ * @return string|false $value
  */
 function update_blog_status( $blog_id, $pref, $value, $deprecated = null ) {
 	global $wpdb;
@@ -828,9 +857,11 @@ function update_blog_status( $blog_id, $pref, $value, $deprecated = null ) {
  *
  * @since MU
  *
- * @param int $id The blog id
+ * @global wpdb $wpdb
+ *
+ * @param int    $id   The blog id
  * @param string $pref A field name
- * @return bool $value
+ * @return bool|string|null $value
  */
 function get_blog_status( $id, $pref ) {
 	global $wpdb;
@@ -847,9 +878,11 @@ function get_blog_status( $id, $pref ) {
  *
  * @since MU
  *
+ * @global wpdb $wpdb
+ *
  * @param mixed $deprecated Not used
- * @param int $start The offset
- * @param int $quantity The maximum number of blogs to retrieve. Default is 40.
+ * @param int   $start      The offset
+ * @param int   $quantity   The maximum number of blogs to retrieve. Default is 40.
  * @return array The list of blogs
  */
 function get_last_updated( $deprecated = '', $start = 0, $quantity = 40 ) {
@@ -868,7 +901,7 @@ function get_last_updated( $deprecated = '', $start = 0, $quantity = 40 ) {
  *
  * @param string $new_status The new post status
  * @param string $old_status The old post status
- * @param object $post Post object
+ * @param object $post       Post object
  */
 function _update_blog_date_on_post_publish( $new_status, $old_status, $post ) {
 	$post_type_obj = get_post_type_object( $post->post_type );
diff --git a/src/wp-includes/ms-default-constants.php b/src/wp-includes/ms-default-constants.php
index 0f7d0ff6d3..05b1eeb2d0 100644
--- a/src/wp-includes/ms-default-constants.php
+++ b/src/wp-includes/ms-default-constants.php
@@ -14,6 +14,8 @@
  * wp-includes/ms-files.php (wp-content/blogs.php in MU).
  *
  * @since 3.0.0
+ *
+ * @global wpdb $wpdb
  */
 function ms_upload_constants() {
 	global $wpdb;
@@ -114,6 +116,9 @@ function ms_file_constants() {
  * we will have translations loaded and can trigger warnings easily.
  *
  * @since 3.0.0
+ *
+ * @staticvar bool $subdomain_error
+ * @staticvar bool $subdomain_error_warn
  */
 function ms_subdomain_constants() {
 	static $subdomain_error = null;
@@ -150,4 +155,3 @@ function ms_subdomain_constants() {
 		define( 'VHOST', 'no' );
 	}
 }
-add_action( 'init', 'ms_subdomain_constants' );
diff --git a/src/wp-includes/ms-default-filters.php b/src/wp-includes/ms-default-filters.php
index 3a3979c111..5fa60baa30 100644
--- a/src/wp-includes/ms-default-filters.php
+++ b/src/wp-includes/ms-default-filters.php
@@ -13,6 +13,8 @@
  * @since 3.0.0
  */
 
+add_action( 'init', 'ms_subdomain_constants' );
+
 // Functions
 add_action( 'update_option_blog_public', 'update_blog_public', 10, 2 );
 add_filter( 'option_users_can_register', 'users_can_register_signup_filter' );
diff --git a/src/wp-includes/ms-functions.php b/src/wp-includes/ms-functions.php
index 43873cabc4..86ea6f894a 100644
--- a/src/wp-includes/ms-functions.php
+++ b/src/wp-includes/ms-functions.php
@@ -28,9 +28,11 @@ function get_sitestats() {
  *
  * @since MU 1.0
  *
+ * @global wpdb $wpdb
+ *
  * @param string $sitedomain Optional. Site domain.
- * @param string $path Optional. Site path.
- * @return array The network admins
+ * @param string $path       Optional. Site path.
+ * @return array|false The network admins
  */
 function get_admin_users_for_domain( $sitedomain = '', $path = '' ) {
 	global $wpdb;
@@ -57,14 +59,16 @@ function get_admin_users_for_domain( $sitedomain = '', $path = '' ) {
  *
  * @since MU 1.0
  *
+ * @global wpdb $wpdb
+ *
  * @param int $user_id The unique ID of the user
- * @return object The blog object
+ * @return object|void The blog object
  */
 function get_active_blog_for_user( $user_id ) {
 	global $wpdb;
 	$blogs = get_blogs_of_user( $user_id );
 	if ( empty( $blogs ) )
-		return null;
+		return;
 
 	if ( !is_multisite() )
 		return $blogs[$wpdb->blogid];
@@ -103,7 +107,7 @@ function get_active_blog_for_user( $user_id ) {
 				}
 			}
 		} else {
-			return null;
+			return;
 		}
 		return $ret;
 	} else {
@@ -166,10 +170,10 @@ function get_blog_post( $blog_id, $post_id ) {
  *
  * @since MU 1.0
  *
- * @param int $blog_id ID of the blog you're adding the user to.
- * @param int $user_id ID of the user you're adding.
- * @param string $role The role you want the user to have
- * @return bool
+ * @param int    $blog_id ID of the blog you're adding the user to.
+ * @param int    $user_id ID of the user you're adding.
+ * @param string $role    The role you want the user to have
+ * @return true|WP_Error
  */
 function add_user_to_blog( $blog_id, $user_id, $role ) {
 	switch_to_blog($blog_id);
@@ -215,10 +219,12 @@ function add_user_to_blog( $blog_id, $user_id, $role ) {
  *
  * @since MU 1.0
  *
- * @param int $user_id ID of the user you're removing.
- * @param int $blog_id ID of the blog you're removing the user from.
+ * @global wpdb $wpdb
+ *
+ * @param int    $user_id  ID of the user you're removing.
+ * @param int    $blog_id  ID of the blog you're removing the user from.
  * @param string $reassign Optional. A user to whom to reassign posts.
- * @return bool
+ * @return true|WP_Error
  */
 function remove_user_from_blog($user_id, $blog_id = '', $reassign = '') {
 	global $wpdb;
@@ -294,11 +300,11 @@ function remove_user_from_blog($user_id, $blog_id = '', $reassign = '') {
  *
  * @since MU 1.0
  *
- * @param string $domain The new blog's domain.
- * @param string $path The new blog's path.
+ * @param string $domain       The new blog's domain.
+ * @param string $path         The new blog's path.
  * @param string $weblog_title The new blog's title.
- * @param int $site_id Optional. Defaults to 1.
- * @return int The ID of the newly created blog
+ * @param int    $site_id      Optional. Defaults to 1.
+ * @return string|int The ID of the newly created blog
  */
 function create_empty_blog( $domain, $path, $weblog_title, $site_id = 1 ) {
 	if ( empty($path) )
@@ -349,8 +355,10 @@ function get_blog_permalink( $blog_id, $post_id ) {
  *
  * @since MU 2.6.5
  *
+ * @global wpdb $wpdb
+ *
  * @param string $domain
- * @param string $path Optional. Not required for subdomain installations.
+ * @param string $path   Optional. Not required for subdomain installations.
  * @return int 0 if no blog found, otherwise the ID of the matching blog
  */
 function get_blog_id_from_url( $domain, $path = '/' ) {
@@ -447,6 +455,8 @@ function is_email_address_unsafe( $user_email ) {
  *
  * @since MU
  *
+ * @global wpdb $wpdb
+ *
  * @param string $user_name  The login name provided by the user.
  * @param string $user_email The email provided by the user.
  * @return array Contains username, email, and error messages.
@@ -569,7 +579,10 @@ function wpmu_validate_user_signup($user_name, $user_email) {
  *
  * @since MU
  *
- * @param string $blogname The blog name provided by the user. Must be unique.
+ * @global wpdb   $wpdb
+ * @global string $domain
+ *
+ * @param string $blogname   The blog name provided by the user. Must be unique.
  * @param string $blog_title The blog title provided by the user.
  * @return array Contains the new site data and error messages.
  */
@@ -700,12 +713,14 @@ function wpmu_validate_blog_signup( $blogname, $blog_title, $user = '' ) {
  *
  * @since MU
  *
- * @param string $domain The requested domain.
- * @param string $path The requested path.
- * @param string $title The requested site title.
- * @param string $user The user's requested login name.
+ * @global wpdb $wpdb
+ *
+ * @param string $domain     The requested domain.
+ * @param string $path       The requested path.
+ * @param string $title      The requested site title.
+ * @param string $user       The user's requested login name.
  * @param string $user_email The user's email address.
- * @param array $meta By default, contains the requested privacy setting and lang_id.
+ * @param array  $meta       By default, contains the requested privacy setting and lang_id.
  */
 function wpmu_signup_blog( $domain, $path, $title, $user, $user_email, $meta = array() )  {
 	global $wpdb;
@@ -735,9 +750,11 @@ function wpmu_signup_blog( $domain, $path, $title, $user, $user_email, $meta = a
  *
  * @since MU
  *
- * @param string $user The user's requested login name.
+ * @global wpdb $wpdb
+ *
+ * @param string $user       The user's requested login name.
  * @param string $user_email The user's email address.
- * @param array $meta By default, this is an empty array.
+ * @param array  $meta       By default, this is an empty array.
  */
 function wpmu_signup_user( $user, $user_email, $meta = array() ) {
 	global $wpdb;
@@ -777,13 +794,13 @@ function wpmu_signup_user( $user, $user_email, $meta = array() ) {
  *
  * @since MU
  *
- * @param string $domain The new blog domain.
- * @param string $path The new blog path.
- * @param string $title The site title.
- * @param string $user The user's login name.
+ * @param string $domain     The new blog domain.
+ * @param string $path       The new blog path.
+ * @param string $title      The site title.
+ * @param string $user       The user's login name.
  * @param string $user_email The user's email address.
- * @param string $key The activation key created in wpmu_signup_blog()
- * @param array $meta By default, contains the requested privacy setting and lang_id.
+ * @param string $key        The activation key created in wpmu_signup_blog()
+ * @param array  $meta       By default, contains the requested privacy setting and lang_id.
  * @return bool
  */
 function wpmu_signup_blog_notification( $domain, $path, $title, $user, $user_email, $key, $meta = array() ) {
@@ -883,10 +900,10 @@ function wpmu_signup_blog_notification( $domain, $path, $title, $user, $user_ema
  *
  * @since MU
  *
- * @param string $user The user's login name.
+ * @param string $user       The user's login name.
  * @param string $user_email The user's email address.
- * @param string $key The activation key created in wpmu_signup_user()
- * @param array $meta By default, an empty array.
+ * @param string $key        The activation key created in wpmu_signup_user()
+ * @param array  $meta       By default, an empty array.
  * @return bool
  */
 function wpmu_signup_user_notification( $user, $user_email, $key, $meta = array() ) {
@@ -963,8 +980,10 @@ function wpmu_signup_user_notification( $user, $user_email, $key, $meta = array(
  *
  * @since MU
  *
+ * @global wpdb $wpdb
+ *
  * @param string $key The activation key provided to the user.
- * @return array An array containing information about the activated user and/or blog
+ * @return array|WP_Error An array containing information about the activated user and/or blog
  */
 function wpmu_activate_signup($key) {
 	global $wpdb;
@@ -1058,9 +1077,9 @@ function wpmu_activate_signup($key) {
  * @since MU
  *
  * @param string $user_name The new user's login name.
- * @param string $password The new user's password.
- * @param string $email The new user's email address.
- * @return int|bool Returns false on failure, or int $user_id on success
+ * @param string $password  The new user's password.
+ * @param string $email     The new user's email address.
+ * @return int|false Returns false on failure, or int $user_id on success
  */
 function wpmu_create_user( $user_name, $password, $email ) {
 	$user_name = preg_replace( '/\s+/', '', sanitize_user( $user_name, true ) );
@@ -1099,13 +1118,13 @@ function wpmu_create_user( $user_name, $password, $email ) {
  *
  * @since MU
  *
- * @param string $domain The new site's domain.
- * @param string $path The new site's path.
- * @param string $title The new site's title.
- * @param int $user_id The user ID of the new site's admin.
- * @param array $meta Optional. Used to set initial site options.
- * @param int $site_id Optional. Only relevant on multi-network installs.
- * @return mixed Returns WP_Error object on failure, int $blog_id on success
+ * @param string $domain  The new site's domain.
+ * @param string $path    The new site's path.
+ * @param string $title   The new site's title.
+ * @param int    $user_id The user ID of the new site's admin.
+ * @param array  $meta    Optional. Used to set initial site options.
+ * @param int    $site_id Optional. Only relevant on multi-network installs.
+ * @return int|WP_Error Returns WP_Error object on failure, int $blog_id on success
  */
 function wpmu_create_blog( $domain, $path, $title, $user_id, $meta = array(), $site_id = 1 ) {
 	$defaults = array( 'public' => 0 );
@@ -1264,9 +1283,11 @@ Disable these notifications: %3$s'), $user->user_login, wp_unslash( $_SERVER['RE
  *
  * @since MU
  *
- * @param string $domain The domain to be checked.
- * @param string $path The path to be checked.
- * @param int $site_id Optional. Relevant only on multi-network installs.
+ * @global wpdb $wpdb
+ *
+ * @param string $domain  The domain to be checked.
+ * @param string $path    The path to be checked.
+ * @param int    $site_id Optional. Relevant only on multi-network installs.
  * @return int
  */
 function domain_exists($domain, $path, $site_id = 1) {
@@ -1295,10 +1316,12 @@ function domain_exists($domain, $path, $site_id = 1) {
  *
  * @since MU
  *
- * @param string $domain The domain of the new site.
- * @param string $path The path of the new site.
- * @param int $site_id Unless you're running a multi-network install, be sure to set this value to 1.
- * @return int The ID of the new row
+ * @global wpdb $wpdb
+ *
+ * @param string $domain  The domain of the new site.
+ * @param string $path    The path of the new site.
+ * @param int    $site_id Unless you're running a multi-network install, be sure to set this value to 1.
+ * @return int|false The ID of the new row
  */
 function insert_blog($domain, $path, $site_id) {
 	global $wpdb;
@@ -1327,7 +1350,10 @@ function insert_blog($domain, $path, $site_id) {
  *
  * @since MU
  *
- * @param int $blog_id The value returned by insert_blog().
+ * @global wpdb     $wpdb
+ * @global WP_Roles $wp_roles
+ *
+ * @param int    $blog_id    The value returned by insert_blog().
  * @param string $blog_title The title of the new site.
  */
 function install_blog( $blog_id, $blog_title = '' ) {
@@ -1381,6 +1407,8 @@ function install_blog( $blog_id, $blog_title = '' ) {
  * @deprecated MU
  * @deprecated Use wp_install_defaults()
  *
+ * @global wpdb $wpdb
+ *
  * @param int $blog_id Ignored in this function.
  * @param int $user_id
  */
@@ -1406,11 +1434,11 @@ function install_blog_defaults($blog_id, $user_id) {
  *
  * @since MU
  *
- * @param int $blog_id
- * @param int $user_id
+ * @param int    $blog_id
+ * @param int    $user_id
  * @param string $password
- * @param string $title The new blog's title
- * @param array $meta Optional. Not used in the default function, but is passed along to hooks for customization.
+ * @param string $title    The new blog's title
+ * @param array  $meta     Optional. Not used in the default function, but is passed along to hooks for customization.
  * @return bool
  */
 function wpmu_welcome_notification( $blog_id, $user_id, $password, $title, $meta = array() ) {
@@ -1509,9 +1537,9 @@ We hope you enjoy your new site. Thanks!
  *
  * @since MU
  *
- * @param int $user_id
+ * @param int    $user_id
  * @param string $password
- * @param array $meta Optional. Not used in the default function, but is passed along to hooks for customization.
+ * @param array  $meta     Optional. Not used in the default function, but is passed along to hooks for customization.
  * @return bool
  */
 function wpmu_welcome_user_notification( $user_id, $password, $meta = array() ) {
@@ -1587,6 +1615,8 @@ function wpmu_welcome_user_notification( $user_id, $password, $meta = array() )
  *
  * @since MU
  *
+ * @global object $current_site
+ *
  * @return object
  */
 function get_current_site() {
@@ -1602,6 +1632,8 @@ function get_current_site() {
  *
  * @since MU
  *
+ * @global wpdb $wpdb
+ *
  * @param int $user_id
  * @return array Contains the blog_id, post_id, post_date_gmt, and post_gmt_ts
  */
@@ -1674,7 +1706,7 @@ function get_dirsize( $directory ) {
  * @since MU
  *
  * @param string $directory
- * @return int
+ * @return int|false
  */
 function recurse_dirsize( $directory ) {
 	$size = 0;
@@ -1737,6 +1769,8 @@ function check_upload_mimes( $mimes ) {
  * are published or unpublished to make sure the count stays current.
  *
  * @since MU
+ *
+ * @global wpdb $wpdb
  */
 function update_posts_count( $deprecated = '' ) {
 	global $wpdb;
@@ -1748,6 +1782,8 @@ function update_posts_count( $deprecated = '' ) {
  *
  * @since MU
  *
+ * @global wpdb $wpdb
+ *
  * @param int $blog_id
  * @param int $user_id
  */
@@ -1765,6 +1801,9 @@ function wpmu_log_new_registrations( $blog_id, $user_id ) {
  *
  * @see term_id_filter
  *
+ * @global wpdb $wpdb
+ * @staticvar int $global_terms_recurse
+ *
  * @param int $term_id An ID for a term on the current blog.
  * @return int An ID from the global terms table mapped from $term_id.
  */
@@ -1846,10 +1885,10 @@ function redirect_this_site( $deprecated = '' ) {
  * @since MU
  *
  * @param array $upload
- * @return mixed If the upload is under the size limit, $upload is returned. Otherwise returns an error message.
+ * @return string|array If the upload is under the size limit, $upload is returned. Otherwise returns an error message.
  */
 function upload_is_file_too_big( $upload ) {
-	if ( is_array( $upload ) == false || defined( 'WP_IMPORTING' ) || get_site_option( 'upload_space_check_disabled' ) )
+	if ( ! is_array( $upload ) || defined( 'WP_IMPORTING' ) || get_site_option( 'upload_space_check_disabled' ) )
 		return $upload;
 
 	if ( strlen( $upload['bits'] )  > ( 1024 * get_site_option( 'fileupload_maxk', 1500 ) ) )
@@ -1921,7 +1960,7 @@ function maybe_redirect_404() {
  */
 function maybe_add_existing_user_to_blog() {
 	if ( false === strpos( $_SERVER[ 'REQUEST_URI' ], '/newbloguser/' ) )
-		return false;
+		return;
 
 	$parts = explode( '/', $_SERVER[ 'REQUEST_URI' ] );
 	$key = array_pop( $parts );
@@ -1944,7 +1983,10 @@ function maybe_add_existing_user_to_blog() {
  *
  * @since MU
  *
+ * @global int $blog_id
+ *
  * @param array $details
+ * @return true|WP_Error|void
  */
 function add_existing_user_to_blog( $details = false ) {
 	global $blog_id;
@@ -1960,8 +2002,8 @@ function add_existing_user_to_blog( $details = false ) {
 		 * @param mixed $result  True on success or a WP_Error object if the user doesn't exist.
 		 */
 		do_action( 'added_existing_user', $details['user_id'], $result );
+		return $result;
 	}
-	return $result;
 }
 
 /**
@@ -1973,7 +2015,7 @@ function add_existing_user_to_blog( $details = false ) {
  * @since MU
  * @see add_user_to_blog()
  *
- * @param int $user_id
+ * @param int   $user_id
  * @param mixed $password Ignored.
  * @param array $meta
  */
@@ -2002,7 +2044,7 @@ function fix_phpmailer_messageid( $phpmailer ) {
  * @since MU
  *
  * @param string|WP_User $user Optional. Defaults to current user. WP_User object,
- * 	or user login name as a string.
+ * 	                           or user login name as a string.
  * @return bool
  */
 function is_user_spammy( $user = null ) {
@@ -2025,7 +2067,7 @@ function is_user_spammy( $user = null ) {
  * @since MU
  *
  * @param int $old_value
- * @param int $value The new public value
+ * @param int $value     The new public value
  */
 function update_blog_public( $old_value, $value ) {
 	update_blog_status( get_current_blog_id(), 'public', (int) $value );
@@ -2036,9 +2078,11 @@ function update_blog_public( $old_value, $value ) {
  *
  * @since MU
  *
+ * @global wpdb $wpdb
+ *
  * @param string $key
- * @param int $user_id Optional. Defaults to current user.
- * @param int $blog_id Optional. Defaults to current blog.
+ * @param int    $user_id Optional. Defaults to current user.
+ * @param int    $blog_id Optional. Defaults to current blog.
  * @return bool
  */
 function is_user_option_local( $key, $user_id = 0, $blog_id = 0 ) {
@@ -2050,10 +2094,7 @@ function is_user_option_local( $key, $user_id = 0, $blog_id = 0 ) {
 	}
 	$local_key = $wpdb->get_blog_prefix( $blog_id ) . $key;
 
-	if ( isset( $current_user->$local_key ) )
-		return true;
-
-	return false;
+	return isset( $current_user->$local_key );
 }
 
 /**
@@ -2065,10 +2106,7 @@ function is_user_option_local( $key, $user_id = 0, $blog_id = 0 ) {
  */
 function users_can_register_signup_filter() {
 	$registration = get_site_option('registration');
-	if ( $registration == 'all' || $registration == 'user' )
-		return true;
-
-	return false;
+	return ( $registration == 'all' || $registration == 'user' );
 }
 
 /**
@@ -2106,6 +2144,8 @@ Thanks!
  *
  * @since 2.8.5
  *
+ * @staticvar bool $forced_content
+ *
  * @param string|bool $force
  * @return bool True if forced, false if not forced.
  */
@@ -2213,6 +2253,8 @@ function wp_maybe_update_network_user_counts() {
  * Update the network-wide site count.
  *
  * @since 3.7.0
+ *
+ * @global wpdb $wpdb
  */
 function wp_update_network_site_counts() {
 	global $wpdb;
@@ -2225,6 +2267,8 @@ function wp_update_network_site_counts() {
  * Update the network-wide user count.
  *
  * @since 3.7.0
+ *
+ * @global wpdb $wpdb
  */
 function wp_update_network_user_counts() {
 	global $wpdb;
@@ -2365,6 +2409,8 @@ function wp_is_large_network( $using = 'sites' ) {
  *
  * @since 3.7.0
  *
+ * @global wpdb $wpdb
+ *
  * @param array $args {
  *     Array of default arguments. Optional.
  *
diff --git a/src/wp-includes/ms-load.php b/src/wp-includes/ms-load.php
index bc925baaa9..e067193f46 100644
--- a/src/wp-includes/ms-load.php
+++ b/src/wp-includes/ms-load.php
@@ -19,10 +19,7 @@ function is_subdomain_install() {
 	if ( defined('SUBDOMAIN_INSTALL') )
 		return SUBDOMAIN_INSTALL;
 
-	if ( defined('VHOST') && VHOST == 'yes' )
-		return true;
-
-	return false;
+	return ( defined( 'VHOST' ) && VHOST == 'yes' );
 }
 
 /**
@@ -68,7 +65,7 @@ function wp_get_active_network_plugins() {
  *
  * @since 3.0.0
  *
- * @return bool|string Returns true on success, or drop-in file to include.
+ * @return true|string Returns true on success, or drop-in file to include.
  */
 function ms_site_check() {
 	$blog = get_blog_details();
@@ -117,10 +114,12 @@ function ms_site_check() {
  *
  * @since 3.9.0
  *
+ * @global wpdb $wpdb
+ *
  * @param string   $domain   Domain to check.
  * @param string   $path     Path to check.
  * @param int|null $segments Path segments to use. Defaults to null, or the full path.
- * @return object|bool Network object if successful. False when no network is found.
+ * @return object|false Network object if successful. False when no network is found.
  */
 function get_network_by_path( $domain, $path, $segments = null ) {
 	global $wpdb;
@@ -260,8 +259,10 @@ function get_network_by_path( $domain, $path, $segments = null ) {
  *
  * @since 3.9.0
  *
+ * @global wpdb $wpdb
+ *
  * @param object|int $network The network's database row or ID.
- * @return object|bool Object containing network information if found, false if not.
+ * @return object|false Object containing network information if found, false if not.
  */
 function wp_get_network( $network ) {
 	global $wpdb;
@@ -281,10 +282,12 @@ function wp_get_network( $network ) {
  *
  * @since 3.9.0
  *
+ * @global wpdb $wpdb
+ *
  * @param string   $domain   Domain to check.
  * @param string   $path     Path to check.
  * @param int|null $segments Path segments to use. Defaults to null, or the full path.
- * @return object|bool Site object if successful. False when no site is found.
+ * @return object|false Site object if successful. False when no site is found.
  */
 function get_site_by_path( $domain, $path, $segments = null ) {
 	global $wpdb;
@@ -391,6 +394,10 @@ function get_site_by_path( $domain, $path, $segments = null ) {
  *
  * @access private
  * @since 3.0.0
+ *
+ * @global wpdb   $wpdb
+ * @global string $domain
+ * @global string $path
  */
 function ms_not_installed() {
 	global $wpdb, $domain, $path;
@@ -463,6 +470,8 @@ function get_current_site_name( $current_site ) {
  * @since 3.0.0
  * @deprecated 3.9.0
  *
+ * @global object $current_site
+ *
  * @return object
  */
 function wpmu_current_site() {