diff --git a/core/includes/session.inc b/core/includes/session.inc
index a514cd5..31e67a6 100644
--- a/core/includes/session.inc
+++ b/core/includes/session.inc
@@ -270,7 +270,7 @@ function drupal_session_initialize() {
 }
 
 /**
- * Starts a session, preserving already set session data.
+ * Starts a session forcefully, preserving already set session data.
  *
  * @ingroup php_wrappers
  */
diff --git a/core/includes/theme.inc b/core/includes/theme.inc
index 4cf6277..646ebe3 100644
--- a/core/includes/theme.inc
+++ b/core/includes/theme.inc
@@ -2984,13 +2984,13 @@ function theme_get_suggestions($args, $base, $delimiter = '__') {
 }
 
 /**
+ * Process variables for maintenance-page.tpl.php.
+ *
  * The variables array generated here is a mirror of
  * template_preprocess_page(). This preprocessor will run its course when
- * theme_maintenance_page() is invoked.
- *
- * An alternate template file of "maintenance-page--offline.tpl.php" can be
- * used when the database is offline to hide errors and completely replace the
- * content.
+ * theme_maintenance_page() is invoked. An alternate template file of
+ * maintenance-page--offline.tpl.php can be used when the database is offline to
+ * hide errors and completely replace the content.
  *
  * The $variables array contains the following arguments:
  * - $content
@@ -3087,11 +3087,13 @@ function template_preprocess_maintenance_page(&$variables) {
 }
 
 /**
- * The variables array generated here is a mirror of template_process_html().
+ * Theme process function for theme_maintenance_field().
  *
+ * 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
+ * @see template_process_html()
  */
 function template_process_maintenance_page(&$variables) {
   $variables['head']    = drupal_get_html_head();
@@ -3103,7 +3105,7 @@ function template_process_maintenance_page(&$variables) {
 /**
  * Preprocess variables for region.tpl.php
  *
- * Prepare the values passed to the theme_region function to be passed into a
+ * Prepares the values passed to the theme_region function to be passed into a
  * pluggable template engine. Uses the region name to generate a template file
  * suggestions. If none are found, the default region.tpl.php is used.
  *
diff --git a/core/includes/theme.maintenance.inc b/core/includes/theme.maintenance.inc
index 4d7cc06..ba88661 100644
--- a/core/includes/theme.maintenance.inc
+++ b/core/includes/theme.maintenance.inc
@@ -2,7 +2,7 @@
 
 /**
  * @file
- * Theming for the maintenance pages.
+ * Theming for maintenance pages.
  */
 
 /**
diff --git a/core/includes/token.inc b/core/includes/token.inc
index 5ed3a5a..5cbb4ee 100644
--- a/core/includes/token.inc
+++ b/core/includes/token.inc
@@ -62,7 +62,7 @@
  *   - langcode: A language code to be used when generating locale-sensitive
  *     tokens.
  *   - callback: A callback function that will be used to post-process the
- *     arrayof token replacements after they are generated. For example, a
+ *     array of token replacements after they are generated. For example, a
  *     module using tokens in a text-only email might provide a callback to
  *     strip HTML entities from token values before they are inserted into the
  *     final text.
@@ -191,7 +191,7 @@ function token_generate($type, array $tokens, array $data = array(), array $opti
 }
 
 /**
- * Returns a list of tokens that being with a specific prefix.
+ * Returns a list of tokens that begin 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 981a810..70a8fde 100644
--- a/core/includes/unicode.inc
+++ b/core/includes/unicode.inc
@@ -2,7 +2,7 @@
 
 /**
  * @file
- * Provides unicode-related conversions and operations.
+ * Provides Unicode-related conversions and operations.
  */
 
 /**
@@ -362,7 +362,7 @@ function mime_header_encode($string) {
  * Decodes MIME/HTTP encoded header values.
  *
  * @param $header
- *   The header to encode.
+ *   The header to decode.
  *
  * @return string
  *   The mime-decoded header.
@@ -377,13 +377,15 @@ function mime_header_decode($header) {
 }
 
 /**
- * Decodes non-encoded header data passed from mime_header_decode().
+ * Decodes encoded header data passed from mime_header_decode().
+ *
+ * Callback for preg_replace_callback() within mime_header_decode().
  *
  * @param $matches
  *   The array of matches from preg_replace_callback().
  *
  * @return string
- *   The mime-decoded header.
+ *   The mime-decoded string.
  *
  * @see mime_header_decode()
  */
@@ -417,7 +419,7 @@ function decode_entities($text) {
 }
 
 /**
- * Counts the amount of characters in a UTF-8 string.
+ * Counts the number of characters in a UTF-8 string.
  *
  * This is less than or equal to the byte count.
  *
@@ -497,7 +499,7 @@ function drupal_strtolower($text) {
  *   An array of matches.
  *
  * @return array
- *   Flips character to Latin-1 version.
+ *   The Latin-1 version of the array of matches.
  *
  * @see drupal_strtolower()
  */
@@ -533,7 +535,7 @@ function drupal_ucfirst($text) {
  * @param $start
  *   The position at which to start reading.
  * @param $length
- *   The amount of characters to read.
+ *   The number of characters to read.
  *
  * @return
  *   The shortened string.
diff --git a/core/includes/update.inc b/core/includes/update.inc
index de4089b..4e4d00e 100644
--- a/core/includes/update.inc
+++ b/core/includes/update.inc
@@ -508,7 +508,7 @@ function update_fix_d8_requirements() {
 }
 
 /**
- * Helps the function to install a new module in Drupal 8 via hook_update_N().
+ * Installs a new module in Drupal 8 via hook_update_N().
  */
 function update_module_enable(array $modules) {
   $schema_store = drupal_container()->get('keyvalue')->get('system.schema');
@@ -547,7 +547,7 @@ function update_module_enable(array $modules) {
 }
 
 /**
- * Performs one update and store the results for display on finished page.
+ * Performs one update and stores the results for display on the results page.
  *
  * If an update function completes successfully, it should return a message
  * as a string indicating success, for example:
@@ -723,7 +723,7 @@ function update_batch($start, $redirect = NULL, $url = NULL, $batch = array(), $
 }
 
 /**
- * Finishes the update process and store results for eventual display.
+ * Finishes the update process and stores the results for eventual display.
  *
  * After the updates run, all caches are flushed. The update results are
  * stored into the session (for example, to be displayed on the update results
@@ -1190,9 +1190,9 @@ function update_variable_del($name) {
 }
 
 /**
- * Updates config with values set on Drupal 7.x
+ * Updates config with values set on Drupal 7.x.
  *
- * Provide a generalised method to migrate variables from Drupal 7 to
+ * Provides a generalised method to migrate variables from Drupal 7 to
  * Drupal 8's configuration management system.
  *
  * @param string $config_name