diff --git a/core/includes/schema.inc b/core/includes/schema.inc
index d87e5c0..b370145 100644
--- a/core/includes/schema.inc
+++ b/core/includes/schema.inc
@@ -124,8 +124,7 @@ function drupal_get_complete_schema($rebuild = FALSE) {
  *
  * @return array|bool
  *   If the module has updates, an array of available updates sorted by
- *   version.
- *   Otherwise, FALSE.
+ *   version. Otherwise, FALSE.
  */
 function drupal_get_schema_versions($module) {
   $updates = &drupal_static(__FUNCTION__, NULL);
diff --git a/core/includes/session.inc b/core/includes/session.inc
index 995b7d4..a514cd5 100644
--- a/core/includes/session.inc
+++ b/core/includes/session.inc
@@ -2,7 +2,7 @@
 
 /**
  * @file
- * Handles the users session functions.
+ * User session handling functions.
  *
  * The user-level session storage handlers:
  * - _drupal_session_open()
diff --git a/core/includes/standard.inc b/core/includes/standard.inc
index 438b177..63f3d70 100644
--- a/core/includes/standard.inc
+++ b/core/includes/standard.inc
@@ -285,8 +285,7 @@ function standard_country_list() {
  * Language codes are defined by the W3C language tags document for
  * interoperability. Language codes typically have a language and optionally,
  * a script or regional variant name. See
- * http://www.w3.org/International/articles/language-tags/ for more
- * information.
+ * http://www.w3.org/International/articles/language-tags/ for more information.
  *
  * This list is based on languages available from localize.drupal.org. See
  * http://localize.drupal.org/issues for information on how to add languages
diff --git a/core/includes/theme.inc b/core/includes/theme.inc
index 6b3efd3..260a196 100644
--- a/core/includes/theme.inc
+++ b/core/includes/theme.inc
@@ -114,8 +114,9 @@ function drupal_theme_initialize() {
 }
 
 /**
- * Initializes the theme system given already loaded information. This
- * function is useful to initialize a theme when no database is present.
+ * Initializes the theme system given already loaded information.
+ *
+ * This function is useful to initialize a theme when no database is present.
  *
  * @param $theme
  *   An object with the following information:
@@ -287,8 +288,7 @@ function theme_get_registry($complete = TRUE) {
 }
 
 /**
- * Sets the callback that will be used by theme_get_registry() to fetch the
- * registry.
+ * Sets the callback that will be used by theme_get_registry().
  *
  * @param $callback
  *   The name of the callback function.
@@ -304,7 +304,7 @@ function _theme_registry_callback($callback = NULL, array $arguments = array())
 }
 
 /**
- * Gets the theme_registry cache; if it doesn't exist, build it.
+ * Gets the theme_registry cache; if it doesn't exist, builds it.
  *
  * @param $theme
  *   The loaded $theme object as returned by list_themes().
@@ -352,9 +352,10 @@ function _theme_save_registry($theme, $registry) {
 }
 
 /**
- * Forces the system to rebuild the theme registry; this should be called
- * when modules are added to the system, or when a dynamic system needs
- * to add more theme hooks.
+ * Forces the system to rebuild the theme registry.
+ *
+ * This function should be called when modules are added to the system, or when
+ * a dynamic system needs to add more theme hooks.
  */
 function drupal_theme_rebuild() {
   drupal_static_reset('theme_get_registry');
@@ -556,7 +557,8 @@ function _theme_process_registry(&$cache, $name, $type, $theme, $path) {
     $cache = $result + $cache;
   }
 
-  // Let themes have variable processors even if they didn't register a template.
+  // Let themes have variable processors even if they didn't register a
+  // template.
   if ($type == 'theme' || $type == 'base_theme') {
     foreach ($cache as $hook => $info) {
       // Check only if not registered by the theme or engine.
@@ -969,7 +971,8 @@ function theme($hook, $variables = array()) {
   // point path_to_theme() to the currently used theme path:
   $theme_path = $info['theme path'];
 
-  // Include a file if the theme function or variable processor is held elsewhere.
+  // Include a file if the theme function or variable processor is held
+  // elsewhere.
   if (!empty($info['includes'])) {
     foreach ($info['includes'] as $include_file) {
       include_once DRUPAL_ROOT . '/' . $include_file;
@@ -1153,8 +1156,7 @@ function path_to_theme() {
 }
 
 /**
- * Allows themes and/or theme engines to easily discover overridden theme
- * functions.
+ * Allows themes and/or theme engines to discover overridden theme functions.
  *
  * @param $cache
  *   The existing cache of theme hooks to test against.
@@ -1308,7 +1310,8 @@ function drupal_find_theme_templates($cache, $extension, $path) {
           if (($pos = strpos($match, '.')) !== FALSE) {
             $file = substr($match, 0, $pos);
           }
-          // Put the underscores back in for the hook name and register this pattern.
+          // Put the underscores back in for the hook name and register this
+          // pattern.
           $arg_name = isset($info['variables']) ? 'variables' : 'render element';
           $implementations[strtr($file, '-', '_')] = array(
             'template' => $file,
@@ -1453,10 +1456,17 @@ function theme_get_setting($setting_name, $theme = NULL) {
  *   The output generated by the template.
  */
 function theme_render_template($template_file, $variables) {
-  extract($variables, EXTR_SKIP);               // Extract the variables to a local namespace
-  ob_start();                                   // Start output buffering
-  include DRUPAL_ROOT . '/' . $template_file;   // Include the template file
-  return ob_get_clean();                        // End buffering and return its contents
+  // Extract the variables to a local namespace
+  extract($variables, EXTR_SKIP);
+
+  // Start output buffering
+  ob_start();
+
+  // Include the template file
+  include DRUPAL_ROOT . '/' . $template_file;
+
+  // End buffering and return its contents
+  return ob_get_clean();
 }
 
 /**
@@ -2472,8 +2482,9 @@ function template_preprocess(&$variables, $hook) {
   global $user;
   static $count = array(), $default_attributes;
 
-  // Track run count for each hook to provide zebra striping.
-  // See "template_preprocess_block()" which provides the same feature specific to blocks.
+  // Track run count for each hook to provide zebra striping. See
+  // "template_preprocess_block()" which provides the same feature specific to
+  // blocks.
   $count[$hook] = isset($count[$hook]) && is_int($count[$hook]) ? $count[$hook] : 1;
   $variables['zebra'] = ($count[$hook] % 2) ? 'odd' : 'even';
   $variables['id'] = $count[$hook]++;
@@ -2794,7 +2805,8 @@ function template_process_html(&$variables) {
  * @return
  *   An array of suggestions, suitable for adding to
  *   $variables['theme_hook_suggestions'] within a preprocess function or to
- *   $variables['attributes']['class'] if the suggestions represent extra CSS classes.
+ *   $variables['attributes']['class'] if the suggestions represent extra CSS
+ *   classes.
  */
 function theme_get_suggestions($args, $base, $delimiter = '__') {
 
@@ -2948,6 +2960,7 @@ function template_preprocess_maintenance_page(&$variables) {
 
 /**
  * The variables array generated here is a mirror of template_process_html().
+ *
  * This processor will run its course when theme_maintenance_page() is invoked.
  *
  * @see maintenance-page.tpl.php
diff --git a/core/includes/theme.maintenance.inc b/core/includes/theme.maintenance.inc
index 4efb469..cd09907 100644
--- a/core/includes/theme.maintenance.inc
+++ b/core/includes/theme.maintenance.inc
@@ -2,7 +2,7 @@
 
 /**
  * @file
- * Themes for maintenance pages.
+ * Theming for the maintenance pages.
  */
 
 /**
@@ -165,8 +165,7 @@ function theme_update_page($variables) {
 }
 
 /**
- * Returns HTML for a report of the results from an operation run via
- * authorize.php.
+ * Returns HTML for a results report of an operation run by authorize.php.
  *
  * @param $variables
  *   An associative array containing:
@@ -195,8 +194,7 @@ function theme_authorize_report($variables) {
 }
 
 /**
- * Returns HTML for a single log message from the authorize.php batch
- * operation.
+ * Returns HTML for a single log message from the authorize.php batch operation.
  *
  * @param $variables
  *   An associative array containing:
diff --git a/core/includes/token.inc b/core/includes/token.inc
index 179b285..5ed3a5a 100644
--- a/core/includes/token.inc
+++ b/core/includes/token.inc
@@ -191,7 +191,7 @@ function token_generate($type, array $tokens, array $data = array(), array $opti
 }
 
 /**
- * Gives a list of tokens and returns those begin with a specific prefix.
+ * Returns a list of tokens that being with a specific prefix.
  *
  * Used to extract a group of 'chained' tokens (such as [node:author:name])
  * from the full list of tokens found in text. For example:
diff --git a/core/includes/unicode.inc b/core/includes/unicode.inc
index e742fba..c08541e 100644
--- a/core/includes/unicode.inc
+++ b/core/includes/unicode.inc
@@ -1,6 +1,11 @@
 <?php
 
 /**
+ * @file
+ * Provides unicode-related conversions and operations.
+ */
+
+/**
  * Matches Unicode characters that are word boundaries.
  *
  * Characters with the following General_category (gc) property values are used
@@ -169,7 +174,7 @@ function drupal_xml_parser_create(&$data) {
 }
 
 /**
- * Converts data to UTF-8
+ * Converts data to UTF-8.
  *
  * Requires the iconv, GNU recode or mbstring PHP extension.
  *
@@ -262,7 +267,7 @@ function drupal_truncate_bytes($string, $len) {
  *   boundaries, giving you "See myverylongurl..." (assuming you had set
  *   $add_ellipses to TRUE).
  *
- * @return
+ * @return string
  *   The truncated string.
  */
 function truncate_utf8($string, $max_length, $wordsafe = FALSE, $add_ellipsis = FALSE, $min_wordsafe_length = 1) {
@@ -315,8 +320,7 @@ function truncate_utf8($string, $max_length, $wordsafe = FALSE, $add_ellipsis =
 }
 
 /**
- * Encodes MIME/HTTP header values that contain non-ASCII, UTF-8 encoded
- * characters.
+ * Encodes MIME/HTTP header values that contain incorrectly encoded characters.
  *
  * For example, mime_header_encode('tést.txt') returns "=?UTF-8?B?dMOpc3QudHh0?=".
  *
@@ -328,6 +332,14 @@ function truncate_utf8($string, $max_length, $wordsafe = FALSE, $add_ellipsis =
  *   each chunk starts and ends on a character boundary.
  * - Using \n as the chunk separator may cause problems on some systems and may
  *   have to be changed to \r\n or \r.
+ *
+ * @param $string
+ *   The header to encode.
+ *
+ * @return string
+ *   The mime-encoded header.
+ *
+ * @see mime_header_decode()
  */
 function mime_header_encode($string) {
   if (preg_match('/[^\x20-\x7E]/', $string)) {
@@ -347,7 +359,15 @@ function mime_header_encode($string) {
 }
 
 /**
- * Complements to mime_header_encode
+ * Decodes MIME/HTTP encoded header values.
+ *
+ * @param $header
+ *   The header to encode.
+ *
+ * @return string
+ *   The mime-decoded header.
+ *
+ * @see mime_header_encode()
  */
 function mime_header_decode($header) {
   // First step: encoded chunks followed by other encoded chunks (need to collapse whitespace)
@@ -357,7 +377,13 @@ function mime_header_decode($header) {
 }
 
 /**
- * Helps the function mime_header_decode
+ * Helper function for mime_header_decode().
+ *
+ * @param $matches
+ *   The array of matches from preg_replace_callback().
+ *
+ * @return string
+ *   The mime-decoded header.
  */
 function _mime_header_decode($matches) {
   // Regexp groups:
@@ -389,8 +415,15 @@ function decode_entities($text) {
 }
 
 /**
- * Counts the amount of characters in a UTF-8 string. This is less than or
- * equal to the byte count.
+ * Counts the amount of characters in a UTF-8 string.
+ *
+ * This is less than or equal to the byte count.
+ *
+ * @param $text
+ *   The string to run the operation on.
+ *
+ * @return integer
+ *   The length of the string.
  *
  * @ingroup php_wrappers
  */
@@ -408,6 +441,12 @@ function drupal_strlen($text) {
 /**
  * Uppercase a UTF-8 string.
  *
+ * @param $text
+ *   The string to run the operation on.
+ *
+ * @return string
+ *   The string in uppercase.
+ *
  * @ingroup php_wrappers
  */
 function drupal_strtoupper($text) {
@@ -427,6 +466,12 @@ function drupal_strtoupper($text) {
 /**
  * Lowercase a UTF-8 string.
  *
+ * @param $text
+ *   The string to run the operation on.
+ *
+ * @return string
+ *   The string in lowercase.
+ *
  * @ingroup php_wrappers
  */
 function drupal_strtolower($text) {
@@ -445,7 +490,14 @@ function drupal_strtolower($text) {
 
 /**
  * Helps the function for case conversion of Latin-1.
+ *
  * Used for flipping U+C0-U+DE to U+E0-U+FD and back.
+ *
+ * @param $matches
+ *   An array of matches.
+ *
+ * @return array
+ *   Flips character to Latin-1 version.
  */
 function _unicode_caseflip($matches) {
   return $matches[0][0] . chr(ord($matches[0][1]) ^ 32);
@@ -454,6 +506,12 @@ function _unicode_caseflip($matches) {
 /**
  * Capitalizes the first letter of a UTF-8 string.
  *
+ * @param $text
+ *   The string to convert.
+ *
+ * @return
+ *   The string with the first letter as uppercase.
+ *
  * @ingroup php_wrappers
  */
 function drupal_ucfirst($text) {
@@ -462,12 +520,21 @@ function drupal_ucfirst($text) {
 }
 
 /**
- * Cuts off a piece of a string based on character indices and counts. Follows
- * the same behavior as PHP's own substr() function.
+ * Cuts off a piece of a string based on character indices and counts.
  *
- * Note that for cutting off a string at a known character/substring
- * location, the usage of PHP's normal strpos/substr is safe and
- * much faster.
+ * Follows the same behavior as PHP's own substr() function. Note that for
+ * cutting off a string at a known character/substring location, the usage of
+ * PHP's normal strpos/substr is safe and much faster.
+ *
+ * @param $text
+ *   The input string.
+ * @param $start
+ *   The position at which to start reading.
+ * @param $length
+ *   The amount of characters to read.
+ *
+ * @return
+ *   The shortened string.
  *
  * @ingroup php_wrappers
  */
diff --git a/core/includes/update.inc b/core/includes/update.inc
index a32cc34..fa9db33 100644
--- a/core/includes/update.inc
+++ b/core/includes/update.inc
@@ -2,7 +2,7 @@
 
 /**
  * @file
- * Updates the API by Drupal Database.
+ * Drupal database update API.
  *
  * This file contains functions to perform database updates for a Drupal
  * installation. It is included and used extensively by update.php.
@@ -487,8 +487,7 @@ function update_prepare_d8_language() {
 }
 
 /**
- * Performs Drupal 7.x to 8.x updates that are required for update.php
- * to function properly.
+ * Performs Drupal 7.x to 8.x required update.php updates.
  *
  * This function runs when update.php is run the first time for 8.x,
  * even before updates are selected or performed. It is important