diff --git a/core/includes/image.inc b/core/includes/image.inc
index f6ae7f1..6191179 100644
--- a/core/includes/image.inc
+++ b/core/includes/image.inc
@@ -34,7 +34,7 @@
  */
 
 /**
- * Return a list of available toolkits.
+ * Returns a list of available toolkits.
  *
  * @return
  *   An array with the toolkit names as keys and the descriptions as values.
@@ -55,7 +55,7 @@ function image_get_available_toolkits() {
 }
 
 /**
- * Retrieve the name of the currently used toolkit.
+ * Retrieves the name of the currently used toolkit.
  *
  * @return
  *   String containing the name of the selected toolkit, or FALSE on error.
@@ -101,7 +101,7 @@ function image_toolkit_invoke($method, stdClass $image, array $params = array())
 }
 
 /**
- * Get details about an image.
+ * Gets details about an image.
  *
  * Drupal supports GIF, JPG and PNG file formats when used with the GD
  * toolkit, and may support others, depending on which toolkits are
@@ -261,7 +261,7 @@ function image_scale(stdClass $image, $width = NULL, $height = NULL, $upscale =
 }
 
 /**
- * Resize an image to the given dimensions (ignoring aspect ratio).
+ * Resizes an image to the given dimensions (ignoring aspect ratio).
  *
  * @param $image
  *   An image object returned by image_load().
@@ -284,7 +284,7 @@ function image_resize(stdClass $image, $width, $height) {
 }
 
 /**
- * Rotate an image by the given number of degrees.
+ * Rotates an image by the given number of degrees.
  *
  * @param $image
  *   An image object returned by image_load().
@@ -308,7 +308,7 @@ function image_rotate(stdClass $image, $degrees, $background = NULL) {
 }
 
 /**
- * Crop an image to the rectangle specified by the given rectangle.
+ * Crops an image to the rectangle specified by the given rectangle.
  *
  * @param $image
  *   An image object returned by image_load().
@@ -340,7 +340,7 @@ function image_crop(stdClass $image, $x, $y, $width, $height) {
 }
 
 /**
- * Convert an image to grayscale.
+ * Converts an image to grayscale.
  *
  * @param $image
  *   An image object returned by image_load().
@@ -357,7 +357,7 @@ function image_desaturate(stdClass $image) {
 
 
 /**
- * Load an image file and return an image object.
+ * Loads an image file and returns an image object.
  *
  * Any changes to the file are not saved until image_save() is called.
  *
@@ -400,7 +400,7 @@ function image_load($file, $toolkit = FALSE) {
 }
 
 /**
- * Close the image and save the changes to a file.
+ * Closes the image and saves the changes to a file.
  *
  * @param $image
  *   An image object returned by image_load(). The object's 'info' property
diff --git a/core/includes/install.core.inc b/core/includes/install.core.inc
index edaf8ec..eb511f8 100644
--- a/core/includes/install.core.inc
+++ b/core/includes/install.core.inc
@@ -13,8 +13,7 @@ use Symfony\Component\HttpFoundation\Response;
  */
 
 /**
- * Global flag to indicate that a task should not be run during the current
- * installation request.
+ * Do not run the task during the current installation request.
  *
  * This can be used to skip running an installation task when certain
  * conditions are met, even though the task may still show on the list of
@@ -27,17 +26,14 @@ use Symfony\Component\HttpFoundation\Response;
 const INSTALL_TASK_SKIP = 1;
 
 /**
- * Global flag to indicate that a task should be run on each installation
- * request that reaches it.
+ * Run the task on each installation request that reaches it.
  *
  * This is primarily used by the Drupal installer for bootstrap-related tasks.
  */
 const INSTALL_TASK_RUN_IF_REACHED = 2;
 
 /**
- * Global flag to indicate that a task should be run on each installation
- * request that reaches it, until the database is set up and we are able to
- * record the fact that it already ran.
+ * Run the task on each installation request until the database is set up.
  *
  * This is the default method for running tasks and should be used for most
  * tasks that occur after the database is set up; these tasks will then run
@@ -214,7 +210,7 @@ function install_state_defaults() {
 }
 
 /**
- * Begin an installation request, modifying the installation state as needed.
+ * Begins an installation request, modifying the installation state as needed.
  *
  * This function performs commands that must run at the beginning of every page
  * request. It throws an exception if the installation should not proceed.
@@ -758,7 +754,7 @@ function install_display_output($output, $install_state) {
 }
 
 /**
- * Installation task; verify the requirements for installing Drupal.
+ * Verifies the requirements for installing Drupal.
  *
  * @param $install_state
  *   An array of information about the current installation state.
@@ -844,7 +840,7 @@ function install_base_system(&$install_state) {
 }
 
 /**
- * Verify and return the last installation task that was completed.
+ * Verifies and returns the last installation task that was completed.
  *
  * @return
  *   The last completed task, if there is one. An exception is thrown if Drupal
@@ -886,7 +882,7 @@ function install_verify_database_settings() {
 }
 
 /**
- * Verify PDO library.
+ * Verifies the PDO library.
  */
 function install_verify_pdo() {
   // PDO was moved to PHP core in 5.2.0, but the old extension (targeting 5.0
@@ -898,15 +894,13 @@ function install_verify_pdo() {
 }
 
 /**
- * Installation task; define a form to configure and rewrite settings.php.
+ * Form constructor for a form to configure and rewrite settings.php.
  *
- * @param $form_state
- *   An associative array containing the current state of the form.
  * @param $install_state
  *   An array of information about the current installation state.
  *
- * @return
- *   The form API definition for the database configuration form.
+ * @see install_settings_form_validate()
+ * @see install_settings_form_submit()
  */
 function install_settings_form($form, &$form_state, &$install_state) {
   global $databases;
@@ -968,7 +962,9 @@ function install_settings_form($form, &$form_state, &$install_state) {
 }
 
 /**
- * Form API validate for install_settings form.
+ * Form validation handler for install_settings_form().
+ *
+ * @see install_settings_form_submit()
  */
 function install_settings_form_validate($form, &$form_state) {
   $driver = $form_state['values']['driver'];
@@ -1029,7 +1025,9 @@ function install_database_errors($database, $settings_file) {
 }
 
 /**
- * Form API submit for install_settings form.
+ * Form submission handler for install_settings_form().
+ *
+ * @see install_settings_form_validate()
  */
 function install_settings_form_submit($form, &$form_state) {
   global $install_state;
@@ -1060,7 +1058,7 @@ function install_settings_form_submit($form, &$form_state) {
 }
 
 /**
- * Installation task; select which profile to install.
+ * Selects which profile to install.
  *
  * @param $install_state
  *   An array of information about the current installation state. The chosen
@@ -1099,8 +1097,7 @@ function install_select_profile(&$install_state) {
 }
 
 /**
- * Helper function for automatically selecting an installation profile from a
- * list or from a selection passed in via $_POST.
+ * Selects an installation profile from a list or from a $_POST submission.
  */
 function _install_select_profile($profiles) {
   // Don't need to choose profile if only one available.
@@ -1114,7 +1111,7 @@ function _install_select_profile($profiles) {
 }
 
 /**
- * Form API array definition for the profile selection form.
+ * Form constructor for the profile selection form.
  *
  * @param array $install_state
  *   An array of information about the current installation state.
@@ -1177,7 +1174,7 @@ function install_select_profile_form($form, &$form_state, $install_state) {
 }
 
 /**
- * Find all .po files useful for the installer.
+ * Finds all .po files that are useful to the installer.
  */
 function install_find_translations() {
   $files = install_find_translation_files();
@@ -1196,7 +1193,7 @@ function install_find_translations() {
 }
 
 /**
- * Find installer translations either for a specific langcode or all languages.
+ * Finds installer translations either for a specific langcode or all languages.
  *
  * @param $langcode
  *   (optional) The language code corresponding to the language for which we
@@ -1216,7 +1213,7 @@ function install_find_translation_files($langcode = NULL) {
 }
 
 /**
- * Installation task; select which language to use.
+ * Selects which language to use during installation.
  *
  * @param $install_state
  *   An array of information about the current installation state. The chosen
@@ -1299,7 +1296,7 @@ function install_select_language(&$install_state) {
 }
 
 /**
- * Form API array definition for language selection.
+ * Form constructor for the language selection form.
  */
 function install_select_language_form($form, &$form_state, $files) {
   include_once DRUPAL_ROOT . '/core/includes/standard.inc';
@@ -1365,7 +1362,7 @@ function install_already_done_error() {
 }
 
 /**
- * Installation task; load information about the chosen profile.
+ * Loads information about the chosen profile during installation.
  *
  * @param $install_state
  *   An array of information about the current installation state. The loaded
@@ -1385,7 +1382,7 @@ function install_load_profile(&$install_state) {
 }
 
 /**
- * Installation task; perform a full bootstrap of Drupal.
+ * Performs a full bootstrap of Drupal during installation.
  *
  * @param $install_state
  *   An array of information about the current installation state.
@@ -1404,7 +1401,7 @@ function install_bootstrap_full(&$install_state) {
 }
 
 /**
- * Installation task; install required modules via a batch process.
+ * Installs required modules via a batch process.
  *
  * @param $install_state
  *   An array of information about the current installation state.
@@ -1457,7 +1454,7 @@ function install_profile_modules(&$install_state) {
 }
 
 /**
- * Installation task; import languages via a batch process.
+ * Imports languages via a batch process during installation.
  *
  * @param $install_state
  *   An array of information about the current installation state.
@@ -1498,15 +1495,13 @@ function install_import_translations(&$install_state) {
 }
 
 /**
- * Installation task; configure settings for the new site.
+ * Form constructor for a form to configure the new site.
  *
- * @param $form_state
- *   An associative array containing the current state of the form.
  * @param $install_state
  *   An array of information about the current installation state.
  *
- * @return
- *   The form API definition for the site configuration form.
+ * @see install_configure_form_validate()
+ * @see install_configure_form_submit()
  */
 function install_configure_form($form, &$form_state, &$install_state) {
   drupal_set_title(st('Configure site'));
@@ -1548,7 +1543,7 @@ function install_configure_form($form, &$form_state, &$install_state) {
 }
 
 /**
- * Installation task; finish importing files at end of installation.
+ * Finishes importing files at end of installation.
  *
  * @param $install_state
  *   An array of information about the current installation state.
@@ -1567,7 +1562,7 @@ function install_import_translations_remaining(&$install_state) {
 }
 
 /**
- * Installation task; perform final steps and display a 'finished' page.
+ * Performs final installation steps and displays a 'finished' page.
  *
  * @param $install_state
  *   An array of information about the current installation state.
@@ -1752,7 +1747,11 @@ function install_check_requirements($install_state) {
 }
 
 /**
- * Forms API array definition for site configuration.
+ * Returns a Forms API array definition for site configuration.
+ *
+ * @see install_configure_form()
+ * @see install_configure_form_validate()
+ * @see install_configure_form_submit()
  */
 function _install_configure_form($form, &$form_state, &$install_state) {
   $form['site_information'] = array(
@@ -1857,7 +1856,9 @@ function _install_configure_form($form, &$form_state, &$install_state) {
 }
 
 /**
- * Forms API validate for the site configuration form.
+ * Form validation handler for install_configure_form().
+ *
+ * @see install_configure_form_submit()
  */
 function install_configure_form_validate($form, &$form_state) {
   if ($error = user_validate_name($form_state['values']['account']['name'])) {
@@ -1866,7 +1867,9 @@ function install_configure_form_validate($form, &$form_state) {
 }
 
 /**
- * Forms API submit for the site configuration form.
+ * Form submission handler for install_configure_form().
+ *
+ * @see install_configure_form_validate()
  */
 function install_configure_form_submit($form, &$form_state) {
   global $user;
diff --git a/core/includes/install.inc b/core/includes/install.inc
index f1184a7..80f2fb1 100644
--- a/core/includes/install.inc
+++ b/core/includes/install.inc
@@ -1,5 +1,10 @@
 <?php
 
+ /**
+ * @file
+ * API functions for installing modules and themes.
+ */
+
 use Drupal\Core\Database\Database;
 use Drupal\locale\Gettext;
 
@@ -74,7 +79,7 @@ const FILE_NOT_WRITABLE = 64;
 const FILE_NOT_EXECUTABLE = 128;
 
 /**
- * Initialize the update system by loading all installed module's .install files.
+ * Loads .install files for installed modules to initialize the update system.
  */
 function drupal_load_updates() {
   foreach (drupal_get_installed_schema_version(NULL, FALSE, TRUE) as $module => $schema_version) {
@@ -109,11 +114,12 @@ function drupal_install_profile_distribution_name() {
 }
 
 /**
- * Auto detect the base_url with PHP predefined variables.
+ * Detects the base URL using the PHP $_SERVER variables.
  *
  * @param $file
  *   The name of the file calling this function so we can strip it out of
  *   the URI when generating the base_url.
+ *
  * @return
  *   The auto-detected $base_url that should be configured in settings.php
  */
@@ -127,7 +133,7 @@ function drupal_detect_baseurl($file = 'core/install.php') {
 }
 
 /**
- * Detect all supported databases that are compiled into PHP.
+ * Detects all supported databases that are compiled into PHP.
  *
  * @return
  *  An array of database types compiled into PHP.
@@ -143,7 +149,7 @@ function drupal_detect_database_types() {
 }
 
 /**
- * Return all supported database installer objects that are compiled into PHP.
+ * Returns all supported database installer objects that are compiled into PHP.
  *
  * @return
  *  An array of database installer objects compiled into PHP.
@@ -182,7 +188,7 @@ function drupal_get_database_types() {
 }
 
 /**
- * Replace values in settings.php with values in the submitted array.
+ * Replaces values in settings.php with values in the submitted array.
  *
  * @param $settings
  *   An array of settings that need to be updated.
@@ -301,10 +307,11 @@ function install_ensure_config_directory() {
 }
 
 /**
- * Verify an install profile for installation.
+ * Verifies an install profile for installation.
  *
  * @param $install_state
  *   An array of information about the current installation state.
+ *
  * @return
  *   The list of modules to install.
  */
@@ -351,7 +358,7 @@ function drupal_verify_profile($install_state) {
 }
 
 /**
- * Callback to install the system module.
+ * Installs the system module.
  *
  * Separated from the installation of other modules so core system
  * functions can be made available while other modules are installed.
@@ -392,7 +399,7 @@ function drupal_install_system() {
 }
 
 /**
- * Verify the state of the specified file.
+ * Verifies the state of the specified file.
  *
  * @param $file
  *   The file to check for.
@@ -400,6 +407,7 @@ function drupal_install_system() {
  *   An optional bitmask created from various FILE_* constants.
  * @param $type
  *   The type of file. Can be file (default), dir, or link.
+ *
  * @return
  *   TRUE on success or FALSE on failure. A message is set for the latter.
  */
@@ -471,7 +479,7 @@ function drupal_verify_install_file($file, $mask = NULL, $type = 'file') {
 }
 
 /**
- * Create a directory with specified permissions.
+ * Creates a directory with the specified permissions.
  *
  * @param $file
  *  The name of the directory to create;
@@ -479,6 +487,7 @@ function drupal_verify_install_file($file, $mask = NULL, $type = 'file') {
  *  The permissions of the directory to create.
  * @param $message
  *  (optional) Whether to output messages. Defaults to TRUE.
+ *
  * @return
  *  TRUE/FALSE whether or not the directory was successfully created.
  */
@@ -510,7 +519,7 @@ function drupal_install_mkdir($file, $mask, $message = TRUE) {
 }
 
 /**
- * Attempt to fix file permissions.
+ * Attempts to fix file permissions.
  *
  * The general approach here is that, because we do not know the security
  * setup of the webserver, we apply our permission changes to all three
@@ -527,6 +536,7 @@ function drupal_install_mkdir($file, $mask, $message = TRUE) {
  *  The desired permissions for the file.
  * @param $message
  *  (optional) Whether to output messages. Defaults to TRUE.
+ *
  * @return
  *  TRUE/FALSE whether or not we were able to fix the file's permissions.
  */
@@ -592,7 +602,7 @@ function drupal_install_fix_file($file, $mask, $message = TRUE) {
 }
 
 /**
- * Send the user to a different installer page.
+ * Sends the user to a different installer page.
  *
  * This issues an on-site HTTP redirect. Messages (and errors) are erased.
  *
@@ -670,7 +680,7 @@ function drupal_requirements_url($severity) {
 }
 
 /**
- * Functional equivalent of t(), used when some systems are not available.
+ * Translates a string when some systems are not available.
  *
  * Used during the install process, when database, theme, and localization
  * system is possibly not yet available.
@@ -729,7 +739,7 @@ function st($string, array $args = array(), array $options = array()) {
 }
 
 /**
- * Check an install profile's requirements.
+ * Checks an install profile's requirements.
  *
  * @param string $profile
  *   Name of install profile to check.
@@ -763,11 +773,12 @@ function drupal_check_profile($profile, array $install_state) {
 }
 
 /**
- * Extract highest severity from requirements array.
+ * Extracts the highest severity from the requirements array.
  *
  * @param $requirements
  *   An array of requirements, in the same format as is returned by
  *   hook_requirements().
+ *
  * @return
  *   The highest severity in the array.
  */
@@ -782,10 +793,11 @@ function drupal_requirements_severity(&$requirements) {
 }
 
 /**
- * Check a module's requirements.
+ * Checks a module's requirements.
  *
  * @param $module
  *   Machine name of module to check.
+ *
  * @return
  *   TRUE/FALSE depending on the requirements are in place.
  */
@@ -812,13 +824,14 @@ function drupal_check_module($module) {
 }
 
 /**
- * Retrieve info about an install profile from its .info file.
+ * Retrieves information about an install profile from its .info file.
  *
  * The information stored in a profile .info file is similar to that stored in
  * a normal Drupal module .info file. For example:
  * - name: The real name of the install profile for display purposes.
  * - description: A brief description of the profile.
- * - dependencies: An array of shortnames of other modules this install profile requires.
+ * - dependencies: An array of shortnames of other modules that this install
+ *   profile requires.
  *
  * Additional, less commonly-used information that can appear in a profile.info
  * file but not in a normal Drupal module .info file includes:
diff --git a/core/includes/language.inc b/core/includes/language.inc
index a243d2e..2a0defa 100644
--- a/core/includes/language.inc
+++ b/core/includes/language.inc
@@ -479,7 +479,7 @@ function language_from_default() {
 }
 
 /**
- * Split the given path into prefix and actual path.
+ * Splits the given path into prefix and actual path.
  *
  * Parse the given path and return the language object identified by the prefix
  * and the actual path.
@@ -512,10 +512,10 @@ function language_url_split_prefix($path, $languages) {
 }
 
 /**
- * Return the possible fallback languages ordered by language weight.
+ * Returns the possible fallback languages ordered by language weight.
  *
  * @param
- *   The language type.
+ *   (optional) The language type. Defaults to LANGUAGE_TYPE_CONTENT.
  *
  * @return
  *   An array of language codes.
diff --git a/core/includes/mail.inc b/core/includes/mail.inc
index b875f92..b5e99bf 100644
--- a/core/includes/mail.inc
+++ b/core/includes/mail.inc
@@ -13,7 +13,7 @@
 define('MAIL_LINE_ENDINGS', isset($_SERVER['WINDIR']) || strpos($_SERVER['SERVER_SOFTWARE'], 'Win32') !== FALSE ? "\r\n" : "\n");
 
 /**
- * Compose and optionally send an e-mail message.
+ * Composes and optionally sends an e-mail message.
  *
  * Sending an e-mail works with defining an e-mail template (subject, text
  * and possibly e-mail headers) and the replacement values to use in the
@@ -195,8 +195,7 @@ function drupal_mail($module, $key, $to, $language, $params = array(), $from = N
 }
 
 /**
- * Returns an object that implements the Drupal\Core\Mail\MailInterface
- * interface.
+ * Returns an object that implements Drupal\Core\Mail\MailInterface.
  *
  * Allows for one or more custom mail backends to format and send mail messages
  * composed using drupal_mail().
@@ -291,7 +290,7 @@ function drupal_mail_system($module, $key) {
 }
 
 /**
- * Perform format=flowed soft wrapping for mail (RFC 3676).
+ * Performs format=flowed soft wrapping for mail (RFC 3676).
  *
  * We use delsp=yes wrapping, but only break non-spaced languages when
  * absolutely necessary to avoid compatibility issues.
@@ -334,8 +333,7 @@ function drupal_wrap_mail($text, $indent = '') {
 }
 
 /**
- * Transform an HTML string into plain text, preserving the structure of the
- * markup. Useful for preparing the body of a node to be sent by e-mail.
+ * Transforms an HTML string into plain text, preserving its structure.
  *
  * The output will be suitable for use as 'format=flowed; delsp=yes' text
  * (RFC 3676) and can be passed directly to drupal_mail() for sending.
@@ -514,9 +512,9 @@ function drupal_html_to_text($string, $allowed_tags = NULL) {
 }
 
 /**
- * Helper function for array_walk in drupal_wrap_mail().
- *
  * Wraps words on a single line.
+ *
+ * Callback for array_walk() winthin drupal_wrap_mail().
  */
 function _drupal_wrap_mail_line(&$line, $key, $values) {
   // Use soft-breaks only for purely quoted or unindented text.
@@ -526,9 +524,9 @@ function _drupal_wrap_mail_line(&$line, $key, $values) {
 }
 
 /**
- * Helper function for drupal_html_to_text().
- *
  * Keeps track of URLs and replaces them with placeholder tokens.
+ *
+ * Callback for preg_replace_callback() within drupal_html_to_text().
  */
 function _drupal_html_to_mail_urls($match = NULL, $reset = FALSE) {
   global $base_url, $base_path;
@@ -553,18 +551,18 @@ function _drupal_html_to_mail_urls($match = NULL, $reset = FALSE) {
 }
 
 /**
- * Helper function for drupal_wrap_mail() and drupal_html_to_text().
+ * Replaces non-quotation markers from a given piece of indentation with spaces.
  *
- * Replace all non-quotation markers from a given piece of indentation with spaces.
+ * Callback for array_map() within drupal_html_to_text().
  */
 function _drupal_html_to_text_clean($indent) {
   return preg_replace('/[^>]/', ' ', $indent);
 }
 
 /**
- * Helper function for drupal_html_to_text().
+ * Pads the last line with the given character.
  *
- * Pad the last line with the given character.
+ * @see drupal_html_to_text()
  */
 function _drupal_html_to_text_pad($text, $pad, $prefix = '') {
   // Remove last line break.
diff --git a/core/includes/menu.inc b/core/includes/menu.inc
index 2fd7b52..87e593d 100644
--- a/core/includes/menu.inc
+++ b/core/includes/menu.inc
@@ -412,9 +412,9 @@ function menu_unserialize($data, $map) {
  * @param $path
  *   The path.
  * @param $router_item
- *   The router item. Usually you take a router entry from menu_get_item and
- *   set it back either modified or to a different path. This lets you modify the
- *   navigation block, the page title, the breadcrumb and the page help in one
+ *   The router item. Usually a router entry from menu_get_item() is either
+ *   modified or set to a different path. This allows the navigation block,
+ *   the page title, the breadcrumb, and the page help to be modified in one
  *   call.
  */
 function menu_set_item($path, $router_item) {
@@ -422,7 +422,7 @@ function menu_set_item($path, $router_item) {
 }
 
 /**
- * Get a router item.
+ * Gets a router item.
  *
  * @param $path
  *   The path, for example node/5. The function will find the corresponding
@@ -551,7 +551,7 @@ function _menu_load_objects(&$item, &$map) {
 }
 
 /**
- * Check access to a menu item using the access callback
+ * Checks access to a menu item using the access callback
  *
  * @param $item
  *   A menu router or menu link item
@@ -583,7 +583,7 @@ function _menu_check_access(&$item, $map) {
 }
 
 /**
- * Localize the router item title using t() or another callback.
+ * Localizes the router item title using t() or another callback.
  *
  * Translate the title and description to allow storage of English title
  * strings in the database, yet display of them in the language required
@@ -765,14 +765,14 @@ function _menu_translate(&$router_item, $map, $to_arg = FALSE) {
 }
 
 /**
- * This function translates the path elements in the map using any to_arg
- * helper function. These functions take an argument and return an object.
- * See http://drupal.org/node/109153 for more information.
+ * Translates the path elements in the map using any to_arg helper function.
  *
  * @param $map
  *   An array of path arguments (ex: array('node', '5'))
  * @param $to_arg_functions
  *   An array of helper function (ex: array(2 => 'menu_tail_to_arg'))
+ *
+ * @see hook_menu()
  */
 function _menu_link_map_translate(&$map, $to_arg_functions) {
   $to_arg_functions = unserialize($to_arg_functions);
@@ -789,14 +789,14 @@ function _menu_link_map_translate(&$map, $to_arg_functions) {
 }
 
 /**
- * Returns path as one string from the argument we are currently at.
+ * Returns a string containing the path relative to the current index.
  */
 function menu_tail_to_arg($arg, $map, $index) {
   return implode('/', array_slice($map, $index));
 }
 
 /**
- * Loads path as one string from the argument we are currently at.
+ * Loads the path as one string relative to the current index.
  *
  * To use this load function, you must specify the load arguments
  * in the router item as:
@@ -813,8 +813,10 @@ function menu_tail_load($arg, &$map, $index) {
 }
 
 /**
- * This function is similar to _menu_translate() but does link-specific
- * preparation such as always calling to_arg functions
+ * Provides menu link access control, translation, and argument handling.
+ *
+ * This function is similar to _menu_translate(), but it also does
+ * link-specific preparation (such as always calling to_arg() functions).
  *
  * @param $item
  *   A menu link.
@@ -908,7 +910,7 @@ function _menu_link_translate(&$item, $translate = FALSE) {
 }
 
 /**
- * Get a loaded object from a router item.
+ * Gets a loaded object from a router item.
  *
  * menu_get_object() provides access to objects loaded by the current router
  * item. For example, on the page node/%node, the router loads the %node object,
@@ -1048,7 +1050,7 @@ function menu_tree_output($tree) {
 }
 
 /**
- * Get the data structure representing a named menu tree.
+ * Gets the data structure representing a named menu tree.
  *
  * Since this can be the full tree including hidden items, the data returned
  * may be used for generating an an admin interface or a select.
@@ -1117,7 +1119,7 @@ function menu_tree_all_data($menu_name, $link = NULL, $max_depth = NULL) {
 }
 
 /**
- * Set the path for determining the active trail of the specified menu tree.
+ * Sets the path for determining the active trail of the specified menu tree.
  *
  * This path will also affect the breadcrumbs under some circumstances.
  * Breadcrumbs are built using the preferred link returned by
@@ -1142,7 +1144,7 @@ function menu_tree_set_path($menu_name, $path = NULL) {
 }
 
 /**
- * Get the path for determining the active trail of the specified menu tree.
+ * Gets the path for determining the active trail of the specified menu tree.
  *
  * @param $menu_name
  *   The menu name of the requested tree.
@@ -1156,7 +1158,7 @@ function menu_tree_get_path($menu_name) {
 }
 
 /**
- * Get the data structure representing a named menu tree, based on the current page.
+ * Gets the data structure for a named menu tree, based on the current page.
  *
  * The tree order is maintained by storing each parent in an individual
  * field, see http://drupal.org/node/141866 for more.
@@ -1292,7 +1294,7 @@ function menu_tree_page_data($menu_name, $max_depth = NULL, $only_active_trail =
 }
 
 /**
- * Build a menu tree, translate links, and check access.
+ * Builds a menu tree, translates links, and checks access.
  *
  * @param $menu_name
  *   The name of the menu.
@@ -1307,8 +1309,8 @@ function menu_tree_page_data($menu_name, $max_depth = NULL, $only_active_trail =
  *     trail. This option is ignored, if 'expanded' is non-empty. Internally
  *     used for breadcrumbs.
  *   - min_depth: The minimum depth of menu links in the resulting tree.
- *     Defaults to 1, which is the default to build a whole tree for a menu, i.e.
- *     excluding menu container itself.
+ *     Defaults to 1, which is the default to build a whole tree for a menu
+ *     (excluding menu container itself).
  *   - max_depth: The maximum depth of menu links in the resulting tree.
  *   - conditions: An associative array of custom database select query
  *     condition key/value pairs; see _menu_build_tree() for the actual query.
@@ -1325,7 +1327,7 @@ function menu_build_tree($menu_name, array $parameters = array()) {
 }
 
 /**
- * Build a menu tree.
+ * Builds a menu tree.
  *
  * This function may be used build the data for a menu tree only, for example
  * to further massage the data manually before further processing happens.
@@ -1423,7 +1425,7 @@ function _menu_build_tree($menu_name, array $parameters = array()) {
 }
 
 /**
- * Recursive helper function - collect node links.
+ * Collects node links from a given menu tree recursively.
  *
  * @param $tree
  *   The menu tree you wish to collect node links from.
@@ -1446,7 +1448,7 @@ function menu_tree_collect_node_links(&$tree, &$node_links) {
 }
 
 /**
- * Check access and perform other dynamic operations for each link in the tree.
+ * Checks access and performs dynamic operations for each link in the tree.
  *
  * @param $tree
  *   The menu tree you wish to operate on.
@@ -1473,7 +1475,7 @@ function menu_tree_check_access(&$tree, $node_links = array()) {
 }
 
 /**
- * Recursive helper function for menu_tree_check_access()
+ * Sorts the menu tree and recursively checks access for each item.
  */
 function _menu_tree_check_access(&$tree) {
   $new_tree = array();
@@ -1496,7 +1498,7 @@ function _menu_tree_check_access(&$tree) {
 }
 
 /**
- * Builds the data representing a menu tree.
+ * Sorts and returns the built data representing a menu tree.
  *
  * @param $links
  *   A flat array of menu links that are part of the menu. Each array element
@@ -1528,7 +1530,7 @@ function menu_tree_data(array $links, array $parents = array(), $depth = 1) {
 }
 
 /**
- * Recursive helper function to build the data representing a menu tree.
+ * Builds the data representing a menu tree.
  *
  * The function is a bit complex because the rendering of a link depends on
  * the next menu link.
@@ -1741,7 +1743,7 @@ function menu_set_custom_theme() {
 }
 
 /**
- * Return an array containing the names of system-defined (default) menus.
+ * Returns an array containing the names of system-defined (default) menus.
  */
 function menu_list_system_menus() {
   return array(
@@ -1753,7 +1755,7 @@ function menu_list_system_menus() {
 }
 
 /**
- * Return an array of links to be rendered as the Main menu.
+ * Returns an array of links to be rendered as the Main menu.
  */
 function menu_main_menu() {
   $config = config('menu.settings');
@@ -1764,7 +1766,7 @@ function menu_main_menu() {
 }
 
 /**
- * Return an array of links to be rendered as the Secondary links.
+ * Returns an array of links to be rendered as the Secondary links.
  */
 function menu_secondary_menu() {
   $config = config('menu.settings');
@@ -1784,7 +1786,7 @@ function menu_secondary_menu() {
 }
 
 /**
- * Return an array of links for a navigation menu.
+ * Returns an array of links for a navigation menu.
  *
  * @param $menu_name
  *   The name of the menu.
@@ -2076,14 +2078,12 @@ function menu_local_tasks($level = 0) {
 }
 
 /**
- * Retrieve contextual links for a system object based on registered local tasks.
+ * Retrieves contextual links for a path based on registered local tasks.
  *
  * This leverages the menu system to retrieve the first layer of registered
  * local tasks for a given system path. All local tasks of the tab type
  * MENU_CONTEXT_INLINE are taken into account.
  *
- * @see hook_menu()
- *
  * For example, when considering the following registered local tasks:
  * - node/%node/view (default local task) with no 'context' defined
  * - node/%node/edit with context: MENU_CONTEXT_PAGE | MENU_CONTEXT_INLINE
@@ -2111,6 +2111,7 @@ function menu_local_tasks($level = 0) {
  *   A list of menu router items that are local tasks for the passed-in path.
  *
  * @see contextual_links_preprocess()
+ * @see hook_menu()
  */
 function menu_contextual_links($module, $parent_path, $args) {
   static $path_empty = array();
@@ -2204,7 +2205,7 @@ function menu_local_actions() {
 }
 
 /**
- * Returns the router path, or the path of the parent tab of a default local task.
+ * Returns the router path, or the path for of a default local task's parent.
  */
 function menu_tab_root_path() {
   $links = menu_local_tasks();
@@ -2247,7 +2248,9 @@ function theme_menu_local_tasks(&$variables) {
 }
 
 /**
- * Set (or get) the active menu for the current page - determines the active trail.
+ * Sets (or gets) the active menu for the current page.
+ *
+ * The active menu for the page determines the active trail.
  *
  * @return
  *   An array of menu machine names, in order of preference. The
@@ -2269,17 +2272,17 @@ function menu_set_active_menu_names($menu_names = NULL) {
 }
 
 /**
- * Get the active menu for the current page - determines the active trail.
+ * Gets the active menu for the current page.
  */
 function menu_get_active_menu_names() {
   return menu_set_active_menu_names();
 }
 
 /**
- * Set the active path, which determines which page is loaded.
+ * Sets the active path, which determines which page is loaded.
  *
  * Note that this may not have the desired effect unless invoked very early
- * in the page load, such as during hook_boot, or unless you do a subrequest
+ * in the page load, such as during hook_boot(), or unless you do a subrequest
  * to generate your page output.
  *
  * @param $path
@@ -2294,7 +2297,7 @@ function menu_set_active_item($path) {
 }
 
 /**
- * Sets the active trail (path to menu tree root) of the current page.
+ * Sets the active trail (path to the menu tree root) of the current page.
  *
  * Any trail set by this function will only be used for functionality that calls
  * menu_get_active_trail(). Drupal core only uses trails set here for
@@ -2384,7 +2387,7 @@ function menu_set_active_trail($new_trail = NULL) {
 }
 
 /**
- * Lookup the preferred menu link for a given system path.
+ * Looks up the preferred menu link for a given system path.
  *
  * @param $path
  *   The path, for example 'node/5'. The function will find the corresponding
@@ -2504,7 +2507,7 @@ function menu_get_active_trail() {
 }
 
 /**
- * Get the breadcrumb for the current page, as determined by the active trail.
+ * Gets the breadcrumb for the current page, as determined by the active trail.
  *
  * @see menu_set_active_trail()
  */
@@ -2555,7 +2558,7 @@ function menu_get_active_breadcrumb() {
 }
 
 /**
- * Get the title of the current page, as determined by the active trail.
+ * Gets the title of the current page, as determined by the active trail.
  */
 function menu_get_active_title() {
   $active_trail = menu_get_active_trail();
@@ -2568,7 +2571,7 @@ function menu_get_active_title() {
 }
 
 /**
- * Get a menu link by its mlid, access checked and link translated for rendering.
+ * Gets a translated, access-checked menu link that is ready for rendering.
  *
  * This function should never be called from within node_load() or any other
  * function used as a menu object load function since an infinite recursion may
@@ -2609,7 +2612,9 @@ function menu_cache_clear($menu_name = 'navigation') {
 }
 
 /**
- * Clears all cached menu data. This should be called any time broad changes
+ * Clears all cached menu data.
+ *
+ * This should be called any time broad changes
  * might have been made to the router items or menu links.
  */
 function menu_cache_clear_all() {
@@ -2630,10 +2635,10 @@ function menu_reset_static_cache() {
 }
 
 /**
- * (Re)populate the database tables used by various menu functions.
+ * Populates the database tables used by various menu functions.
  *
  * This function will clear and populate the {menu_router} table, add entries
- * to {menu_links} for new router items, then remove stale items from
+ * to {menu_links} for new router items, and then remove stale items from
  * {menu_links}.
  *
  * @return
@@ -2671,7 +2676,7 @@ function menu_router_rebuild() {
 }
 
 /**
- * Collect and alter the menu definitions.
+ * Collects and alters the menu definitions.
  */
 function menu_router_build() {
   // We need to manually call each module so that we can know which module
@@ -2695,7 +2700,7 @@ function menu_router_build() {
 }
 
 /**
- * Helper function to store the menu router if we have it in memory.
+ * Stores the menu router if we have it in memory.
  */
 function _menu_router_cache($new_menu = NULL) {
   $menu = &drupal_static(__FUNCTION__);
@@ -2707,7 +2712,7 @@ function _menu_router_cache($new_menu = NULL) {
 }
 
 /**
- * Get the menu router.
+ * Gets the menu router.
  */
 function menu_get_router() {
   // Check first if we have it in memory already.
@@ -2744,7 +2749,7 @@ function _menu_link_build($item) {
 }
 
 /**
- * Helper function to build menu links for the items in the menu router.
+ * Builds menu links for the items in the menu router.
  */
 function _menu_navigation_links_rebuild($menu) {
   // Add normal and suggested items as links.
@@ -2844,7 +2849,7 @@ function _menu_navigation_links_rebuild($menu) {
 }
 
 /**
- * Clone an array of menu links.
+ * Clones an array of menu links.
  *
  * @param $links
  *   An array of menu links to clone.
@@ -2935,12 +2940,14 @@ function menu_link_delete($mlid, $path = NULL) {
 }
 
 /**
- * Helper function for menu_link_delete; deletes a single menu link.
+ * Deletes a single menu link.
  *
  * @param $item
  *   Item to be deleted.
  * @param $force
  *   Forces deletion. Internal use only, setting to TRUE is discouraged.
+ *
+ * @see menu_link_delete()
  */
 function _menu_delete_item($item, $force = FALSE) {
   $item = is_object($item) ? get_object_vars($item) : $item;
@@ -3152,7 +3159,7 @@ function menu_link_save(&$item, $existing_item = array(), $parent_candidates = a
 }
 
 /**
- * Find a possible parent for a given menu link.
+ * Finds a possible parent for a given menu link.
  *
  * Because the parent of a given link might not exist anymore in the database,
  * we apply a set of heuristics to determine a proper parent:
@@ -3166,6 +3173,7 @@ function menu_link_save(&$item, $existing_item = array(), $parent_candidates = a
  *   A menu link.
  * @param $parent_candidates
  *   An array of menu links keyed by mlid.
+ *
  * @return
  *   A menu link structure of the possible parent or FALSE if no valid parent
  *   has been found.
@@ -3231,7 +3239,7 @@ function _menu_link_find_parent($menu_link, $parent_candidates = array()) {
 }
 
 /**
- * Helper function to clear the page and block caches at most twice per page load.
+ * Clears the page and block caches at most twice per page load.
  */
 function _menu_clear_page_cache() {
   $cache_cleared = &drupal_static(__FUNCTION__, 0);
@@ -3253,7 +3261,7 @@ function _menu_clear_page_cache() {
 }
 
 /**
- * Helper function to update a list of menus with expanded items
+ * Updates a list of menus with expanded items.
  */
 function _menu_set_expanded_menus() {
   $names = db_query("SELECT menu_name FROM {menu_links} WHERE expanded <> 0 GROUP BY menu_name")->fetchCol();
@@ -3261,7 +3269,7 @@ function _menu_set_expanded_menus() {
 }
 
 /**
- * Find the router path which will serve this path.
+ * Finds the router path which will serve this path.
  *
  * @param $link_path
  *  The path for we are looking up its router path.
@@ -3303,7 +3311,7 @@ function _menu_find_router_path($link_path) {
 }
 
 /**
- * Insert, update or delete an uncustomized menu link related to a module.
+ * Inserts, updates, or deletes an uncustomized menu link related to a module.
  *
  * @param $module
  *   The name of the module.
@@ -3343,7 +3351,7 @@ function menu_link_maintain($module, $op, $link_path, $link_title) {
 }
 
 /**
- * Find the depth of an item's children relative to its depth.
+ * Finds the depth of an item's children relative to its depth.
  *
  * For example, if the item has a depth of 2, and the maximum of any child in
  * the menu link tree is 5, the relative depth is 3.
@@ -3375,7 +3383,7 @@ function menu_link_children_relative_depth($item) {
 }
 
 /**
- * Update the children of a menu link that's being moved.
+ * Updates the children of a menu link that is being moved.
  *
  * The menu name, parents (p1 - p6), and depth are updated for all children of
  * the link, and the has_children status of the previous parent is updated.
@@ -3424,7 +3432,7 @@ function _menu_link_move_children($item, $existing_item) {
 }
 
 /**
- * Check and update the has_children status for the parent of a link.
+ * Checks and updates the 'has_children' status for the parent of a link.
  */
 function _menu_update_parental_status($item, $exclude = FALSE) {
   // If plid == 0, there is nothing to update.
@@ -3448,7 +3456,7 @@ function _menu_update_parental_status($item, $exclude = FALSE) {
 }
 
 /**
- * Helper function that sets the p1..p9 values for a menu link being saved.
+ * Sets the p1 through p9 values for a menu link being saved.
  */
 function _menu_link_parents_set(&$item, $parent) {
   $i = 1;
@@ -3466,7 +3474,7 @@ function _menu_link_parents_set(&$item, $parent) {
 }
 
 /**
- * Helper function to build the router table based on the data from hook_menu.
+ * Builds the router table based on the data from hook_menu().
  */
 function _menu_router_build($callbacks) {
   // First pass: separate callbacks from paths, making paths ready for
@@ -3690,7 +3698,7 @@ function _menu_router_build($callbacks) {
 }
 
 /**
- * Helper function to save data from menu_router_build() to the router table.
+ * Saves data from menu_router_build() to the router table.
  */
 function _menu_router_save($menu, $masks) {
   // Delete the existing router since we have some data to replace it.
diff --git a/core/includes/module.inc b/core/includes/module.inc
index ab45576..0442b77 100644
--- a/core/includes/module.inc
+++ b/core/includes/module.inc
@@ -9,7 +9,7 @@ use Drupal\Component\Graph\Graph;
 use Drupal\Core\Config\DatabaseStorage;
 
 /**
- * Load all the modules that have been enabled in the system table.
+ * Loads all the modules that have been enabled in the system table.
  *
  * @param $bootstrap
  *   Whether to load only the reduced set of modules loaded in "bootstrap mode"
@@ -98,7 +98,7 @@ function module_list_reset() {
 }
 
 /**
- * Build a list of bootstrap modules and enabled modules and themes.
+ * Builds a list of bootstrap modules and enabled modules and themes.
  *
  * @param $type
  *   The type of list to return:
@@ -213,7 +213,7 @@ function system_list($type) {
 }
 
 /**
- * Reset all system_list() caches.
+ * Resets all system_list() caches.
  */
 function system_list_reset() {
   drupal_static_reset('system_list');
@@ -224,7 +224,7 @@ function system_list_reset() {
 }
 
 /**
- * Find dependencies any level deep and fill in required by information too.
+ * Determines which modules require and are required by each module.
  *
  * @param $files
  *   The array of filesystem objects used to rebuild the cache.
@@ -257,7 +257,7 @@ function _module_build_dependencies($files) {
 }
 
 /**
- * Determine whether a given module exists.
+ * Determines whether a given module exists.
  *
  * @param $module
  *   The name of the module (without the .module extension).
@@ -271,7 +271,7 @@ function module_exists($module) {
 }
 
 /**
- * Load a module's installation hooks.
+ * Loads a module's installation hooks.
  *
  * @param $module
  *   The name of the module (without the .module extension).
@@ -287,7 +287,7 @@ function module_load_install($module) {
 }
 
 /**
- * Load a module include file.
+ * Loads a module include file.
  *
  * Examples:
  * @code
@@ -329,8 +329,7 @@ function module_load_include($type, $module, $name = NULL) {
 }
 
 /**
- * Load an include file for each of the modules that have been enabled in
- * the system table.
+ * Loads an include file for each module enabled in the {system} table.
  */
 function module_load_all_includes($type, $name = NULL) {
   $modules = module_list();
@@ -504,7 +503,7 @@ function module_enable($module_list, $enable_dependencies = TRUE) {
 }
 
 /**
- * Disable a given set of modules.
+ * Disables a given set of modules.
  *
  * @param $module_list
  *   An array of module names.
@@ -675,7 +674,7 @@ function module_uninstall($module_list = array(), $uninstall_dependents = TRUE)
  */
 
 /**
- * Determine whether a module implements a hook.
+ * Determines whether a module implements a hook.
  *
  * @param $module
  *   The name of the module (without the .module extension).
@@ -704,7 +703,7 @@ function module_hook($module, $hook) {
 }
 
 /**
- * Determine which modules are implementing a hook.
+ * Determines which modules are implementing a hook.
  *
  * @param $hook
  *   The name of the hook (e.g. "help" or "menu").
@@ -778,7 +777,7 @@ function module_implements($hook) {
 }
 
 /**
- * Regenerate the stored list of hook implementations.
+ * Regenerates the stored list of hook implementations.
  */
 function module_implements_reset() {
   // We maintain a persistent cache of hook implementations in addition to the
@@ -799,7 +798,7 @@ function module_implements_reset() {
 }
 
 /**
- * Retrieve a list of what hooks are explicitly declared.
+ * Retrieves a list of what hooks are explicitly declared.
  */
 function module_hook_info() {
   // When this function is indirectly invoked from bootstrap_invoke_all() prior
@@ -862,7 +861,7 @@ function module_implements_write_cache() {
 }
 
 /**
- * Invoke a hook in a particular module.
+ * Invokes a hook in a particular module.
  *
  * @param $module
  *   The name of the module (without the .module extension).
@@ -884,7 +883,7 @@ function module_invoke($module, $hook) {
 }
 
 /**
- * Invoke a hook in all enabled modules that implement it.
+ * Invokes a hook in all enabled modules that implement it.
  *
  * @param $hook
  *   The name of the hook to invoke.
@@ -941,7 +940,7 @@ function drupal_required_modules() {
 }
 
 /**
- * Hands off alterable variables to type-specific *_alter implementations.
+ * Passes alterable variables to specific hook_TYPE_alter() implementations.
  *
  * This dispatch function hands off the passed-in variables to type-specific
  * hook_TYPE_alter() implementations in modules. It ensures a consistent