diff --git a/includes/install.core.inc b/includes/install.core.inc
index 3cf90636d7b..1dbe9e2f82c 100644
--- a/includes/install.core.inc
+++ b/includes/install.core.inc
@@ -43,7 +43,7 @@ define('INSTALL_TASK_RUN_IF_REACHED', 2);
 define('INSTALL_TASK_RUN_IF_NOT_COMPLETED', 3);
 
 /**
- * Install Drupal either interactively or via an array of passed-in settings.
+ * Installs Drupal either interactively or via an array of passed-in settings.
  *
  * The Drupal installation happens in a series of steps, which may be spread
  * out over multiple page requests. Each request begins by trying to determine
@@ -107,7 +107,7 @@ function install_drupal($settings = array()) {
 }
 
 /**
- * Return an array of default settings for the global installation state.
+ * Returns an array of default settings for the global installation state.
  *
  * The installation state is initialized with these settings at the beginning
  * of each page request. They may evolve during the page request, but they are
@@ -312,7 +312,7 @@ function install_begin_request(&$install_state) {
 }
 
 /**
- * Run all tasks for the current installation request.
+ * Runs all tasks for the current installation request.
  *
  * In the case of an interactive installation, all tasks will be attempted
  * until one is reached that has output which needs to be displayed to the
@@ -322,6 +322,7 @@ function install_begin_request(&$install_state) {
  * @param $install_state
  *   An array of information about the current installation state. This is
  *   passed along to each task, so it can be modified if necessary.
+ *
  * @return
  *   HTML output from the last completed task.
  */
@@ -363,13 +364,14 @@ function install_run_tasks(&$install_state) {
 }
 
 /**
- * Run an individual installation task.
+ * Runs an individual installation task.
  *
  * @param $task
  *   An array of information about the task to be run.
  * @param $install_state
  *   An array of information about the current installation state. This is
  *   passed in by reference so that it can be modified by the task.
+ *
  * @return
  *   The output of the task function, if there is any.
  */
@@ -469,7 +471,7 @@ function install_run_task($task, &$install_state) {
 }
 
 /**
- * Return a list of tasks to perform during the current installation request.
+ * Returns a list of tasks to perform during the current installation request.
  *
  * Note that the list of tasks can change based on the installation state as
  * the page request evolves (for example, if an installation profile hasn't
@@ -477,6 +479,7 @@ function install_run_task($task, &$install_state) {
  *
  * @param $install_state
  *   An array of information about the current installation state.
+ *
  * @return
  *   A list of tasks to be performed, with associated metadata.
  */
@@ -499,7 +502,7 @@ function install_tasks_to_perform($install_state) {
 }
 
 /**
- * Return a list of all tasks the installer currently knows about.
+ * Returns a list of all tasks the installer currently knows about.
  *
  * This function will return tasks regardless of whether or not they are
  * intended to run on the current page request. However, the list can change
@@ -509,6 +512,7 @@ function install_tasks_to_perform($install_state) {
  *
  * @param $install_state
  *   An array of information about the current installation state.
+ *
  * @return
  *   A list of tasks, with associated metadata.
  */
@@ -610,13 +614,14 @@ function install_tasks($install_state) {
 }
 
 /**
- * Return a list of tasks that should be displayed to the end user.
+ * Returns a list of tasks that should be displayed to the end user.
  *
  * The output of this function is a list suitable for sending to
  * theme_task_list().
  *
  * @param $install_state
  *   An array of information about the current installation state.
+ *
  * @return
  *   A list of tasks, with keys equal to the machine-readable task name and
  *   values equal to the name that should be displayed.
@@ -634,12 +639,13 @@ function install_tasks_to_display($install_state) {
 }
 
 /**
- * Return the URL that should be redirected to during an installation request.
+ * Returns the URL that should be redirected to during an installation request.
  *
  * The output of this function is suitable for sending to install_goto().
  *
  * @param $install_state
  *   An array of information about the current installation state.
+ *
  * @return
  *   The URL to redirect to.
  *
@@ -650,11 +656,11 @@ function install_redirect_url($install_state) {
 }
 
 /**
- * Return the complete URL that should be redirected to during an installation
- * request.
+ * Returns the complete URL redirected to during an installation request.
  *
  * @param $install_state
  *   An array of information about the current installation state.
+ *
  * @return
  *   The complete URL to redirect to.
  *
@@ -666,7 +672,7 @@ function install_full_redirect_url($install_state) {
 }
 
 /**
- * Display themed installer output and end the page request.
+ * Displays themed installer output and ends the page request.
  *
  * Installation tasks should use drupal_set_title() to set the desired page
  * title, but otherwise this function takes care of theming the overall page
@@ -697,6 +703,7 @@ function install_display_output($output, $install_state) {
  *
  * @param $install_state
  *   An array of information about the current installation state.
+ *
  * @return
  *   A themed status report, or an exception if there are requirement errors.
  *   Otherwise, no output is returned, so that the next task can be run
@@ -784,7 +791,7 @@ function install_verify_completed_task() {
 }
 
 /**
- * Verify existing settings.php
+ * Verifies the existing settings in settings.php.
  */
 function install_verify_settings() {
   global $db_prefix, $databases;
@@ -816,6 +823,7 @@ function install_verify_pdo() {
  *   An associative array containing the current state of the form.
  * @param $install_state
  *   An array of information about the current installation state.
+ *
  * @return
  *   The form API definition for the database configuration form.
  */
@@ -846,7 +854,7 @@ function install_settings_form($form, &$form_state, &$install_state) {
     $form['driver']['#description'] .= ' ' . st('Your PHP configuration only supports the %driver database type so it has been automatically selected.', array('%driver' => current($drivers)));
   }
 
-  // Database name
+  // Database name.
   $form['database'] = array(
     '#type' => 'textfield',
     '#title' => st('Database name'),
@@ -856,7 +864,7 @@ function install_settings_form($form, &$form_state, &$install_state) {
     '#description' => st('The name of the database your @drupal data will be stored in. It must exist on your server before @drupal can be installed.', array('@drupal' => drupal_install_profile_distribution_name())),
   );
 
-  // Database username
+  // Database username.
   $form['username'] = array(
     '#type' => 'textfield',
     '#title' => st('Database username'),
@@ -864,7 +872,7 @@ function install_settings_form($form, &$form_state, &$install_state) {
     '#size' => 45,
   );
 
-  // Database password
+  // Database password.
   $form['password'] = array(
     '#type' => 'password',
     '#title' => st('Database password'),
@@ -880,7 +888,7 @@ function install_settings_form($form, &$form_state, &$install_state) {
     '#description' => st("These options are only necessary for some sites. If you're not sure what you should enter here, leave the default settings or check with your hosting provider.")
   );
 
-  // Database host
+  // Database host.
   $form['advanced_options']['host'] = array(
     '#type' => 'textfield',
     '#title' => st('Database host'),
@@ -892,7 +900,7 @@ function install_settings_form($form, &$form_state, &$install_state) {
     '#description' => st('If your database is located on a different server, change this.'),
   );
 
-  // Database port
+  // Database port.
   $form['advanced_options']['port'] = array(
     '#type' => 'textfield',
     '#title' => st('Database port'),
@@ -903,7 +911,7 @@ function install_settings_form($form, &$form_state, &$install_state) {
     '#description' => st('If your database server is listening to a non-standard port, enter its number.'),
   );
 
-  // Table prefix
+  // Table prefix.
   $db_prefix = ($profile == 'standard') ? 'drupal_' : $profile . '_';
   $form['advanced_options']['db_prefix'] = array(
     '#type' => 'textfield',
@@ -938,12 +946,12 @@ function install_settings_form_validate($form, &$form_state) {
 }
 
 /**
- * Check a database connection and return any errors.
+ * Checks a database connection and returns any errors.
  */
 function install_database_errors($database, $settings_file) {
   global $databases;
   $errors = array();
-  // Verify the table prefix
+  // Verify the table prefix.
   if (!empty($database['db_prefix']) && is_string($database['db_prefix']) && !preg_match('/^[A-Za-z0-9_.]+$/', $database['db_prefix'])) {
     $errors['db_prefix'] = st('The database table prefix you have entered, %db_prefix, is invalid. The table prefix can only contain alphanumeric characters, periods, or underscores.', array('%db_prefix' => $database['db_prefix']));
   }
@@ -952,7 +960,7 @@ function install_database_errors($database, $settings_file) {
     $errors['db_port'] = st('Database port must be a number.');
   }
 
-  // Check database type
+  // Check database type.
   $database_types = drupal_detect_database_types();
   $driver = $database['driver'];
   if (!isset($database_types[$driver])) {
@@ -960,7 +968,7 @@ function install_database_errors($database, $settings_file) {
   }
   else {
     // Run tasks associated with the database type. Any errors are caught in the
-    // calling function
+    // calling function.
     $databases['default']['default'] = $database;
     // Just changing the global doesn't get the new information processed.
     // We tell tell the Database class to re-parse $databases.
@@ -986,7 +994,7 @@ function install_settings_form_submit($form, &$form_state) {
   global $install_state;
 
   $database = array_intersect_key($form_state['values']['_database'], array_flip(array('driver', 'database', 'username', 'password', 'host', 'port')));
-  // Update global settings array and save
+  // Update global settings array and save.
   $settings['databases'] = array(
     'value'    => array('default' => array('default' => $database)),
     'required' => TRUE,
@@ -1009,7 +1017,7 @@ function install_settings_form_submit($form, &$form_state) {
 }
 
 /**
- * Find all .profile files.
+ * Finds all .profile files.
  */
 function install_find_profiles() {
   return file_scan_directory('./profiles', '/\.profile$/', array('key' => 'name'));
@@ -1022,6 +1030,7 @@ function install_find_profiles() {
  *   An array of information about the current installation state. The chosen
  *   profile will be added here, if it was not already selected previously, as
  *   will a list of all available profiles.
+ *
  * @return
  *   For interactive installations, a form allowing the profile to be selected,
  *   if the user has a choice that needs to be made. Otherwise, an exception is
@@ -1154,6 +1163,7 @@ function install_find_locales($profilename) {
  *   An array of information about the current installation state. The chosen
  *   locale will be added here, if it was not already selected previously, as
  *   will a list of all available locales.
+ *
  * @return
  *   For interactive installations, a form or other page output allowing the
  *   locale to be selected or providing information about locale selection, if
@@ -1243,7 +1253,7 @@ function install_select_locale_form($form, &$form_state, $locales, $profilename
   include_once DRUPAL_ROOT . '/includes/iso.inc';
   $languages = _locale_get_predefined_list();
   foreach ($locales as $locale) {
-    // Try to use verbose locale name
+    // Try to use verbose locale name.
     $name = $locale->name;
     if (isset($languages[$name])) {
       $name = $languages[$name][0] . (isset($languages[$name][1]) ? ' ' . st('(@language)', array('@language' => $languages[$name][1])) : '');
@@ -1270,7 +1280,7 @@ function install_select_locale_form($form, &$form_state, $locales, $profilename
 }
 
 /**
- * Indicate that there are no profiles available.
+ * Indicates that there are no profiles available.
  */
 function install_no_profile_error() {
   drupal_set_title(st('No profiles available'));
@@ -1278,7 +1288,7 @@ function install_no_profile_error() {
 }
 
 /**
- * Indicate that Drupal has already been installed.
+ * Indicates that Drupal has already been installed.
  */
 function install_already_done_error() {
   global $base_url;
@@ -1326,6 +1336,7 @@ function install_bootstrap_full(&$install_state) {
  *
  * @param $install_state
  *   An array of information about the current installation state.
+ *
  * @return
  *   The batch definition.
  */
@@ -1350,6 +1361,7 @@ function install_profile_modules(&$install_state) {
  *
  * @param $install_state
  *   An array of information about the current installation state.
+ *
  * @return
  *   The batch definition, if there are language files to import.
  */
@@ -1374,6 +1386,7 @@ function install_import_locales(&$install_state) {
  *   An associative array containing the current state of the form.
  * @param $install_state
  *   An array of information about the current installation state.
+ *
  * @return
  *   The form API definition for the site configuration form.
  */
@@ -1428,6 +1441,7 @@ function install_configure_form($form, &$form_state, &$install_state) {
  *
  * @param $install_state
  *   An array of information about the current installation state.
+ *
  * @return
  *   The batch definition, if there are language files to import.
  */
@@ -1447,6 +1461,7 @@ function install_import_locales_remaining(&$install_state) {
  *
  * @param $install_state
  *   An array of information about the current installation state.
+ *
  * @return
  *   A message informing the user that the installation is complete.
  */
@@ -1507,7 +1522,7 @@ function _install_module_batch($module, $module_name, &$context) {
 }
 
 /**
- * Check installation requirements and report any errors.
+ * Checks installation requirements and reports any errors.
  */
 function install_check_requirements($install_state) {
   $profile = $install_state['parameters']['profile'];
@@ -1567,7 +1582,7 @@ function install_check_requirements($install_state) {
 }
 
 /**
- * Form API array definition for site configuration.
+ * Forms API array definition for site configuration.
  */
 function _install_configure_form($form, &$form_state, &$install_state) {
   include_once DRUPAL_ROOT . '/includes/locale.inc';
@@ -1680,7 +1695,7 @@ function _install_configure_form($form, &$form_state, &$install_state) {
 }
 
 /**
- * Form API validate for the site configuration form.
+ * Forms API validate for the site configuration form.
  */
 function install_configure_form_validate($form, &$form_state) {
   if ($error = user_validate_name($form_state['values']['account']['name'])) {
@@ -1695,7 +1710,7 @@ function install_configure_form_validate($form, &$form_state) {
 }
 
 /**
- * Form API submit for the site configuration form.
+ * Forms API submit for the site configuration form.
  */
 function install_configure_form_submit($form, &$form_state) {
   global $user;
diff --git a/sites/default/default.settings.php b/sites/default/default.settings.php
index d748aa4b5bf..6a3a4a77d52 100644
--- a/sites/default/default.settings.php
+++ b/sites/default/default.settings.php
@@ -155,7 +155,7 @@ $databases = array();
 $db_prefix = '';
 
 /**
- * Access control for update.php script
+ * Access control for update.php script.
  *
  * If you are updating your Drupal installation using the update.php script but
  * are not logged in using either an account with the "Administer software
diff --git a/update.php b/update.php
index af43c756533..960eb7ef382 100644
--- a/update.php
+++ b/update.php
@@ -21,10 +21,10 @@ define('DRUPAL_ROOT', getcwd());
  */
 
 /**
- * Global flag to identify update.php run, and so avoid various unwanted
- * operations, such as hook_init() and hook_exit() invokes, css/js preprocessing
- * and translation, and solve some theming issues. This flag is checked on several
- * places in Drupal code (not just update.php).
+ * Global flag indicating that update.php is being run.
+ *
+ * When this flag is set, various operations do not take place, such as invoking
+ * hook_init() and hook_exit(), css/js preprocessing, and translation.
  */
 define('MAINTENANCE_MODE', 'update');
 
@@ -47,7 +47,7 @@ function update_script_selection_form($form, &$form_state) {
     '#collapsible' => TRUE,
   );
 
-  // Ensure system.module's updates appear first
+  // Ensure system.module's updates appear first.
   $form['start']['system'] = array();
 
   $updates = update_get_update_list();
@@ -137,7 +137,8 @@ function update_script_selection_form($form, &$form_state) {
 }
 
 function update_helpful_links() {
-  // NOTE: we can't use l() here because the URL would point to 'update.php?q=admin'.
+  // NOTE: we can't use l() here because the URL would point to
+  // 'update.php?q=admin'.
   $links[] = '<a href="' . base_path() . '">Front page</a>';
   $links[] = '<a href="' . base_path() . '?q=admin">Administration pages</a>';
   return $links;
@@ -148,7 +149,7 @@ function update_results_page() {
   $links = update_helpful_links();
 
   update_task_list();
-  // Report end result
+  // Report end result.
   if (module_exists('dblog')) {
     $log_message = ' All errors have been <a href="' . base_path() . '?q=admin/reports/dblog">logged</a>.';
   }
@@ -174,7 +175,7 @@ function update_results_page() {
 
   $output .= theme('item_list', array('items' => $links));
 
-  // Output a list of queries executed
+  // Output a list of queries executed.
   if (!empty($_SESSION['update_results'])) {
     $output .= '<div id="update-results">';
     $output .= '<h2>The following updates returned messages</h2>';
@@ -397,7 +398,7 @@ if (update_access_allowed()) {
 
   $op = isset($_REQUEST['op']) ? $_REQUEST['op'] : '';
   switch ($op) {
-    // update.php ops
+    // update.php ops.
 
     case 'selection':
       if (isset($_GET['token']) && $_GET['token'] == drupal_get_token('update')) {
@@ -419,7 +420,7 @@ if (update_access_allowed()) {
       $output = update_results_page();
       break;
 
-    // Regular batch ops : defer to batch processing API
+    // Regular batch ops : defer to batch processing API.
     default:
       update_task_list('run');
       $output = _batch_page();