diff --git a/core/modules/locale/lib/Drupal/locale/Gettext.php b/core/modules/locale/lib/Drupal/locale/Gettext.php
index a7c37ca..5db756e 100644
--- a/core/modules/locale/lib/Drupal/locale/Gettext.php
+++ b/core/modules/locale/lib/Drupal/locale/Gettext.php
@@ -31,7 +31,7 @@ class Gettext {
    *   List of file objects with URI properties pointing to read.
    *
    * @return array
-   *   Structured array as produced by a PoMemoryWriter.
+   *   A structured array as produced by a PoMemoryWriter.
    *
    * @see Drupal\Component\Gettext\PoMemoryWriter
    */
@@ -53,24 +53,25 @@ static function filesToArray($langcode, array $files) {
    *
    * @param stdClass $file
    *   File object with an URI property pointing at the file's path.
-   *
    * @param array $options
    *   An array with options that can have the following elements:
-   *   - 'langcode': The language code, required.
-   *   - 'overwrite_options': Overwrite options array as defined in
-   *     Drupal\locale\PoDatabaseWriter. Optional, defaults to an empty array.
-   *   - 'customized': Flag indicating whether the strings imported from $file
-   *     are customized translations or come from a community source. Use
-   *     LOCALE_CUSTOMIZED or LOCALE_NOT_CUSTOMIZED. Optional, defaults to
+   *   - langcode: (required) The language code.
+   *   - overwrite_options: (optional) Overwrite options array as defined in
+   *     Drupal\locale\PoDatabaseWriter. Defaults to an empty array.
+   *   - customized: (optional) A flag indicating whether the strings imported
+   *     from $file are customized translations or come from a community source.
+   *     Use LOCALE_CUSTOMIZED or LOCALE_NOT_CUSTOMIZED. Defaults to
    *     LOCALE_NOT_CUSTOMIZED.
-   *   - 'seek': Specifies from which position in the file should the reader
-   *     start reading the next items. Optional, defaults to 0.
-   *   - 'items': Specifies the number of items to read. Optional, defaults to
+   *   - seek: (optional) Specifies from which position in the file should the
+   *     reader start reading the next items. Defaults to zero.
+   *   - items: (optional) Specifies the number of items to read. Defaults to
    *     -1, which means that all the items from the stream will be read.
    *
    * @return array
    *   Report array as defined in Drupal\locale\PoDatabaseWriter.
    *
+   * @throws \Exception
+   *
    * @see Drupal\locale\PoDatabaseWriter
    */
   static function fileToDatabase($file, $options) {
diff --git a/core/modules/locale/lib/Drupal/locale/LocaleConfigSubscriber.php b/core/modules/locale/lib/Drupal/locale/LocaleConfigSubscriber.php
index 3d2fd4a..6fe4dc9 100644
--- a/core/modules/locale/lib/Drupal/locale/LocaleConfigSubscriber.php
+++ b/core/modules/locale/lib/Drupal/locale/LocaleConfigSubscriber.php
@@ -19,7 +19,7 @@
  */
 class LocaleConfigSubscriber implements EventSubscriberInterface {
   /**
-   * Override configuration values with localized data.
+   * Overrides configuration values with localized data.
    *
    * @param Drupal\Core\Config\ConfigEvent $event
    *   The Event to process.
@@ -34,10 +34,18 @@ public function configLoad(ConfigEvent $event) {
   }
 
   /**
-   * Get configuration name for this language.
+   * Gets configuration name for this language.
    *
    * It will be the same name with a prefix depending on language code:
-   * locale.config.LANGCODE.NAME
+   * - locale.config.LANGCODE.NAME
+   *
+   * @param string $name
+   *   The configuration name of a given language.
+   * @param object $langcode
+   *   A language code object.
+   *
+   * @return string
+   *   The configuration name of a language as a string.
    */
   public function getLocaleConfigName($name, $language) {
     return 'locale.config.' . $language->langcode . '.' . $name;
diff --git a/core/modules/locale/lib/Drupal/locale/LocaleLookup.php b/core/modules/locale/lib/Drupal/locale/LocaleLookup.php
index c2be228..210ad6d 100644
--- a/core/modules/locale/lib/Drupal/locale/LocaleLookup.php
+++ b/core/modules/locale/lib/Drupal/locale/LocaleLookup.php
@@ -18,25 +18,34 @@ class LocaleLookup extends CacheArray {
 
   /**
    * A language code.
+   *
    * @var string
    */
   protected $langcode;
 
   /**
    * The msgctxt context.
+   *
    * @var string
    */
   protected $context;
 
   /**
-   * The locale storage
+   * The locale storage location.
    *
    * @var Drupal\locale\StringStorageInterface
    */
   protected $stringStorage;
 
   /**
-   * Constructs a LocaleCache object.
+   * Constructs a LocaleLookup object.
+   *
+   * @param string $langcode
+   *   A language code.
+   * @param string $context
+   *   The msgctxt context.
+   * @param \Drupal\locale\StringStorageInterface $stringStorage
+   *   The locale storage location.
    */
   public function __construct($langcode, $context, $stringStorage) {
     $this->langcode = $langcode;
diff --git a/core/modules/locale/lib/Drupal/locale/PoDatabaseReader.php b/core/modules/locale/lib/Drupal/locale/PoDatabaseReader.php
index 74cf40d..f09b6d5 100644
--- a/core/modules/locale/lib/Drupal/locale/PoDatabaseReader.php
+++ b/core/modules/locale/lib/Drupal/locale/PoDatabaseReader.php
@@ -22,10 +22,10 @@ class PoDatabaseReader implements PoReaderInterface {
    * An associative array indicating which type of strings should be read.
    *
    * Elements of the array:
-   *  - not_customized: boolean indicating if not customized strings should be
+   *  - not_customized: A Boolean indicating if not customized strings should be
    *    read.
-   *  - customized: boolean indicating if customized strings should be read.
-   *  - no_translated: boolean indicating if non-translated should be read.
+   *  - customized: A Boolean indicating if customized strings should be read.
+   *  - no_translated: A Boolean indicating if non-translated should be read.
    *
    * The three options define three distinct sets of strings, which combined
    * cover all strings.
@@ -42,14 +42,14 @@ class PoDatabaseReader implements PoReaderInterface {
   private $_langcode;
 
   /**
-   * Store the result of the query so it can be iterated later.
+   * Stores the result of the query so it can be iterated later.
    *
    * @var resource
    */
   private $_result;
 
   /**
-   * Constructor, initializes with default options.
+   * Constructs a PoDatabaseReader object.
    */
   function __construct() {
     $this->setOptions(array());
@@ -71,6 +71,9 @@ public function setLangcode($langcode) {
 
   /**
    * Get the options used by the reader.
+   *
+   * @return array
+   *   An associative array indicating which type of strings should be read.
    */
   function getOptions() {
     return $this->_options;
@@ -78,6 +81,9 @@ function getOptions() {
 
   /**
    * Set the options for the current reader.
+   *
+   * @param array $options
+   *   An associative array indicating which type of strings should be read.
    */
   function setOptions(array $options) {
     $options += array(
@@ -98,7 +104,7 @@ function getHeader() {
   /**
    * Implements Drupal\Component\Gettext\PoMetadataInterface::setHeader().
    *
-   * @throws Exception
+   * @throws \Exception
    *   Always, because you cannot set the PO header of a reader.
    */
   function setHeader(PoHeader $header) {
@@ -155,6 +161,9 @@ private function loadStrings() {
 
   /**
    * Get the database result resource for the given language and options.
+   *
+   * @return resource
+   *   The results of a query for a given language and options.
    */
   private function readString() {
     if (!isset($this->_result)) {
diff --git a/core/modules/locale/lib/Drupal/locale/PoDatabaseWriter.php b/core/modules/locale/lib/Drupal/locale/PoDatabaseWriter.php
index b5b03c0..a27e7a3 100644
--- a/core/modules/locale/lib/Drupal/locale/PoDatabaseWriter.php
+++ b/core/modules/locale/lib/Drupal/locale/PoDatabaseWriter.php
@@ -24,11 +24,11 @@ class PoDatabaseWriter implements PoWriterInterface {
    *
    * Elements of the array:
    * - override_options
-   *   - not_customized: boolean indicating that not customized strings should
+   *   - not_customized: A Boolean indicating that not customized strings should
    *     be overwritten.
-   *   - customized: boolean indicating that customized strings should be
+   *   - customized: A Boolean indicating that customized strings should be
    *     overwritten.
-   * - customized: the strings being imported should be saved as customized.
+   * - customized: The strings being imported should be saved as customized.
    *     One of LOCALE_CUSTOMIZED or LOCALE_NOT_CUSTOMIZED.
    *
    * @var array
@@ -50,20 +50,20 @@ class PoDatabaseWriter implements PoWriterInterface {
   private $_header;
 
   /**
-   * Associative array summarizing the number of changes done.
+   * An associative array summarizing the number of changes done.
    *
-   * Keys for the array:
-   *  - additions: number of source strings newly added
-   *  - updates: number of translations updated
-   *  - deletes: number of translations deleted
-   *  - skips: number of strings skipped due to disallowed HTML
+   * The keys for the array are:
+   *  - additions: The number of source strings newly added.
+   *  - updates: The number of translations updated.
+   *  - deletes: The number of translations deleted.
+   *  - skips: The number of strings skipped due to disallowed HTML.
    *
    * @var array
    */
   private $_report;
 
   /**
-   * Constructor, initialize reporting array.
+   * Constructs a PoDatabaseWriter object.
    */
   function __construct() {
     $this->setReport();
@@ -84,17 +84,21 @@ public function setLangcode($langcode) {
   }
 
   /**
-   * Get the report of the write operations.
+   * Gets the report of the write operations.
+   *
+   * @return array
+   *   An associative array with report result information.
    */
   public function getReport() {
     return $this->_report;
   }
 
   /**
-   * Set the report array of write operations.
+   * Sets the report array of write operations.
    *
    * @param array $report
-   *   Associative array with result information.
+   *   (optional) An associative array with result information. Defaults to an
+   *   empty array.
    */
   function setReport($report = array()) {
     $report += array(
@@ -108,7 +112,10 @@ function setReport($report = array()) {
   }
 
   /**
-   * Get the options used by the writer.
+   * Gets the options used by the writer.
+   *
+   * @return array
+   *   An associative array indicating what data should be overwritten.
    */
   function getOptions() {
     return $this->_options;
@@ -116,6 +123,9 @@ function getOptions() {
 
   /**
    * Set the options for the current writer.
+   *
+   * @param array $options
+   *   An associative array indicating what data should be overwritten.
    */
   function setOptions(array $options) {
     if (!isset($options['overwrite_options'])) {
diff --git a/core/modules/locale/lib/Drupal/locale/StringBase.php b/core/modules/locale/lib/Drupal/locale/StringBase.php
index e2d9bcc..4c89145 100644
--- a/core/modules/locale/lib/Drupal/locale/StringBase.php
+++ b/core/modules/locale/lib/Drupal/locale/StringBase.php
@@ -60,7 +60,7 @@
    * Constructs a new locale string object.
    *
    * @param object|array $values
-   *   Object or array with initial values.
+   *   An object or array with initial values.
    */
   public function __construct($values = array()) {
     $this->setValues((array)$values);
diff --git a/core/modules/locale/lib/Drupal/locale/StringDatabaseStorage.php b/core/modules/locale/lib/Drupal/locale/StringDatabaseStorage.php
index 33138e7..453db45 100644
--- a/core/modules/locale/lib/Drupal/locale/StringDatabaseStorage.php
+++ b/core/modules/locale/lib/Drupal/locale/StringDatabaseStorage.php
@@ -39,6 +39,7 @@ class StringDatabaseStorage implements StringStorageInterface {
    *   A Database connection to use for reading and writing configuration data.
    * @param array $options
    *   (optional) Any additional database connection options to use in queries.
+   *   Defaults to an empty array.
    */
   public function __construct(Connection $connection, array $options = array()) {
     $this->connection = $connection;
@@ -285,10 +286,10 @@ protected function dbStringTable($string) {
    * @param Drupal\locale\StringInterface $string
    *   The string object.
    * @param string $table
-   *   (optional) The table name.
+   *   (optional) The table name. Defaults to NULL.
    *
-   * @return array
-   *   Array with key fields if the string has all keys, or empty array if not.
+   * @return array|null
+   *   Array with key fields if the string has all keys, or NULL if not.
    */
   protected function dbStringKeys($string, $table = NULL) {
     $table = $table ? $table : $this->dbStringTable($string);
@@ -308,7 +309,7 @@ protected function dbStringKeys($string, $table = NULL) {
    * @param Drupal\locale\StringInterface $string
    *   The string object.
    * @param string $table
-   *   (optional) The table name.
+   *   (optional) The table name. Defaults to NULL.
    *
    * @return array
    *   Array with field values indexed by field name.
@@ -330,7 +331,7 @@ protected function dbStringValues($string, $table = NULL) {
    * @param Drupal\locale\StringInterface $string
    *   The string object.
    * @param string $table
-   *   (optional) The table name.
+   *   (optional) The table name. Defaults to NULL.
    */
   protected function dbStringDefaults($string, $table = NULL) {
     $table = $table ? $table : $this->dbStringTable($string);
@@ -385,6 +386,8 @@ protected function dbStringLoad(array $conditions, array $options, $class) {
    *   these additional ones:
    *   - 'translation', Whether to include translation fields too. Defaults to
    *     FALSE.
+   *   Defaults to an empty array.
+   *
    * @return SelectQuery
    *   Query object with all the tables, fields and conditions.
    */
@@ -487,17 +490,17 @@ protected function dbStringSelect(array $conditions, array $options = array()) {
   }
 
   /**
-   * Createds a database record for a string object.
+   * Creates a database record for a string object.
    *
    * @param Drupal\locale\StringInterface $string
    *   The string object.
    *
-   * @return bool|int
+   * @return bool|int|false
    *   If the operation failed, returns FALSE.
    *   If it succeeded returns the last insert ID of the query, if one exists.
    *
    * @throws Drupal\locale\StringStorageException
-   *   If the string is not suitable for this storage, an exception ithrown.
+   *   If the string is not suitable for this storage, an exception is thrown.
    */
   protected function dbStringInsert($string) {
     if (($table = $this->dbStringTable($string)) && ($fields = $this->dbStringValues($string, $table))) {
@@ -519,7 +522,7 @@ protected function dbStringInsert($string) {
    * @param Drupal\locale\StringInterface $string
    *   The string object.
    *
-   * @return bool|int
+   * @return int|false
    *   If the record update failed, returns FALSE. If it succeeded, returns
    *   SAVED_NEW or SAVED_UPDATED.
    *
@@ -563,6 +566,14 @@ protected function dbDelete($table, $keys) {
 
   /**
    * Executes an arbitrary SELECT query string.
+   *
+   * @param ??? $query
+   *   ???
+   * @param array $args
+   *   ???
+   *
+   * @return ???
+   *   ???
    */
   protected function dbExecute($query, array $args = array()) {
     return $this->connection->query($query, $args, $this->options);
diff --git a/core/modules/locale/lib/Drupal/locale/StringStorageInterface.php b/core/modules/locale/lib/Drupal/locale/StringStorageInterface.php
index d02774f..5479229 100644
--- a/core/modules/locale/lib/Drupal/locale/StringStorageInterface.php
+++ b/core/modules/locale/lib/Drupal/locale/StringStorageInterface.php
@@ -28,6 +28,7 @@
    *   any of the following optional keys:
    *   - 'filters': Array of string filters indexed by field name.
    *   - 'pager limit': Use pager and set this limit value.
+   *   Defaults to an empty array.
    *
    * @return array
    *   Array of Drupal\locale\StringInterface objects matching the conditions.
@@ -42,13 +43,14 @@ public function getStrings(array $conditions = array(), array $options = array()
    * @param array $conditions
    *   (optional) Array with conditions that will be used to filter the strings
    *   returned and may include all of the conditions defined by getStrings().
+   *   Defaults to an empty array.
    * @param array $options
    *   (optional) An associative array of additional options. It may contain
-   *   any of the options defined by getStrings().
+   *   any of the options defined by getStrings(). Defaults to an empty array.
    *
    * @return array
    *   Array of Drupal\locale\StringInterface objects matching the conditions.
-  */
+   */
   public function getTranslations(array $conditions = array(), array $options = array());
 
   /**
@@ -76,8 +78,8 @@ public function getLocations(array $conditions = array());
    * in a single page request.
    *
    * @param array $conditions
-   *   (optional) Array with conditions that will be used to filter the strings
-   *   returned and may include all of the conditions defined by getStrings().
+   *   An array with conditions that will be used to filter the strings returned
+   *   and may include all of the conditions defined by getStrings().
    *
    * @return Drupal\locale\SourceString|null
    *   Minimal TranslationString object if found, NULL otherwise.
@@ -101,7 +103,7 @@ public function findString(array $conditions);
   public function findTranslation(array $conditions);
 
   /**
-   * Save string object to storage.
+   * Saves the string object to storage.
    *
    * @param Drupal\locale\StringInterface $string
    *   The string object.
@@ -115,7 +117,7 @@ public function findTranslation(array $conditions);
   public function save($string);
 
   /**
-   * Delete string from storage.
+   * Deletes the string object from storage.
    *
    * @param Drupal\locale\StringInterface $string
    *   The string object.
@@ -161,10 +163,10 @@ public function countStrings();
   public function countTranslations();
 
   /**
-   * Creates a source string object bound to this storage but not saved.
+   * Creates a source string object bound to this storage, but not saved.
    *
    * @param array $values
-   *   (optional) Array with initial values. Defaults to empty array.
+   *   (optional) Array with initial values. Defaults to an empty array.
    *
    * @return Drupal\locale\SourceString
    *   New source string object.
@@ -172,10 +174,10 @@ public function countTranslations();
   public function createString($values = array());
 
   /**
-   * Creates a string translation object bound to this storage but not saved.
+   * Creates a string translation object bound to this storage, but not saved.
    *
    * @param array $values
-   *   (optional) Array with initial values. Defaults to empty array.
+   *   (optional) Array with initial values. Defaults to an empty array.
    *
    * @return Drupal\locale\TranslationString
    *   New string translation object.
diff --git a/core/modules/locale/lib/Drupal/locale/Tests/LocaleCompareTest.php b/core/modules/locale/lib/Drupal/locale/Tests/LocaleCompareTest.php
index 017e2c5..365d374 100644
--- a/core/modules/locale/lib/Drupal/locale/Tests/LocaleCompareTest.php
+++ b/core/modules/locale/lib/Drupal/locale/Tests/LocaleCompareTest.php
@@ -10,7 +10,12 @@
 use Drupal\simpletest\WebTestBase;
 
 /**
- * Tests for comparing status of existing project translations with available translations.
+ * Tests for the project status functionality in the Locale module.
+ *
+ * This classe checks the status of existing project translations with what
+ * translations are available.  This class uses German as default test language.
+ * Due to hardcoded configurations in the locale_test module, a language can not
+ * be chosen randomly.
  */
 class LocaleCompareTest extends WebTestBase {
 
@@ -36,12 +41,6 @@ public static function getInfo() {
     );
   }
 
-  /**
-   * Setup the test environment.
-   *
-   * We use German as default test language. Due to hardcoded configurations in
-   * the locale_test module, the language can not be chosen randomly.
-   */
   function setUp() {
     parent::setUp();
     module_load_include('compare.inc', 'locale');
@@ -51,7 +50,7 @@ function setUp() {
   }
 
   /**
-   * Set the value of the default translations directory.
+   * Sets the value of the default translations directory.
    *
    * @param string $path
    *   Path of the translations directory relative to the drupal installation
@@ -67,13 +66,15 @@ private function setTranslationsDirectory($path) {
    * Creates a translation file and tests its timestamp.
    *
    * @param string $path
-   *   Path of the file relative to the public file path.
+   *   The path of the file relative to the public file path.
    * @param string $filename
-   *   Name of the file to create.
+   *   The name of the file to create.
    * @param integer $timestamp
-   *   Timestamp to set the file to. Defaults to current time.
+   *   (optional) A timestamp to set the file to, in seconds. Defaults to NULL,
+   *   which in turn implies to use the current time.
    * @param string $data
-   *   Translation data to put into the file. Po header data will be added.
+   *   (optional) The translation data to put into the file. Po header data will
+   *    be added. Defaults to an empty string.
    */
   private function makePoFile($path, $filename, $timestamp = NULL, $data = '') {
     $timestamp = $timestamp ? $timestamp : REQUEST_TIME;
@@ -104,7 +105,7 @@ private function makePoFile($path, $filename, $timestamp = NULL, $data = '') {
   }
 
   /**
-   * Test for translation status storage and translation status comparison.
+   * Tests for translation status storage and translation status comparison.
    */
   function testLocaleCompare() {
     // Create and login user.
diff --git a/core/modules/locale/lib/Drupal/locale/Tests/LocaleContentTest.php b/core/modules/locale/lib/Drupal/locale/Tests/LocaleContentTest.php
index bc74778..364e10c 100644
--- a/core/modules/locale/lib/Drupal/locale/Tests/LocaleContentTest.php
+++ b/core/modules/locale/lib/Drupal/locale/Tests/LocaleContentTest.php
@@ -30,7 +30,7 @@ public static function getInfo() {
   }
 
   /**
-   * Verifies that machine name fields are always LTR.
+   * Verifies that machine name fields are always Left-to-Right.
    */
   function testMachineNameLTR() {
     // User to add and remove language.
@@ -58,7 +58,7 @@ function testMachineNameLTR() {
   }
 
   /**
-   * Test if a content type can be set to multilingual and language is present.
+   * Tests if a content type can be set to multilingual and language is present.
    */
   function testContentTypeLanguageConfiguration() {
     global $base_url;
@@ -133,7 +133,7 @@ function testContentTypeLanguageConfiguration() {
   }
 
   /**
-   * Test if a dir and lang tags exist in node's attributes.
+   * Tests if a dir and lang tags exist in node's attributes.
    */
   function testContentTypeDirLang() {
     $type = $this->drupalCreateContentType();
diff --git a/core/modules/locale/lib/Drupal/locale/Tests/LocaleExportTest.php b/core/modules/locale/lib/Drupal/locale/Tests/LocaleExportTest.php
index 7ae1bf7..1c05d09 100644
--- a/core/modules/locale/lib/Drupal/locale/Tests/LocaleExportTest.php
+++ b/core/modules/locale/lib/Drupal/locale/Tests/LocaleExportTest.php
@@ -31,6 +31,8 @@ public static function getInfo() {
 
   /**
    * A user able to create languages and export translations.
+   *
+   * @var object
    */
   protected $admin_user = NULL;
 
@@ -46,7 +48,7 @@ function setUp() {
   }
 
   /**
-   * Test exportation of translations.
+   * Tests the exportation of translations functionality.
    */
   function testExportTranslation() {
     // First import some known translations.
@@ -115,7 +117,7 @@ function testExportTranslation() {
   }
 
   /**
-   * Test exportation of translation template file.
+   * Tests the exportation of translation template file.
    */
   function testExportTranslationTemplateFile() {
     // Load an admin page with JavaScript so drupal_add_library() fires at least
@@ -129,7 +131,7 @@ function testExportTranslationTemplateFile() {
   }
 
   /**
-   * Helper function that returns a proper .po file.
+   * Returns a proper .po file.
    */
   function getPoFile() {
     return <<< EOF
@@ -147,8 +149,7 @@ function getPoFile() {
   }
 
   /**
-   * Helper function that returns a .po file which strings will be marked
-   * as customized.
+   * Returns a .po file with some strings marked as customized.
    */
   function getCustomPoFile() {
     return <<< EOF
diff --git a/core/modules/locale/lib/Drupal/locale/Tests/LocaleFileImportStatus.php b/core/modules/locale/lib/Drupal/locale/Tests/LocaleFileImportStatus.php
index 06d292f..83010cb 100644
--- a/core/modules/locale/lib/Drupal/locale/Tests/LocaleFileImportStatus.php
+++ b/core/modules/locale/lib/Drupal/locale/Tests/LocaleFileImportStatus.php
@@ -41,7 +41,7 @@ function setUp() {
   }
 
   /**
-   * Add a language.
+   * Adds a language.
    *
    * @param $langcode
    *   The language of the langcode to add.
@@ -54,7 +54,7 @@ function addLanguage($langcode) {
   }
 
   /**
-   * Get translations for an array of strings.
+   * Retrieves translations for an array of strings.
    *
    * @param $strings
    *   An array of strings to translate.
@@ -69,12 +69,13 @@ function checkTranslations($strings, $langcode) {
   }
 
   /**
-   * Import a single interface translation file.
+   * Imports a single interface translation file.
    *
    * @param $langcode
    *   Langcode of the po file and language to import.
    * @param int $timestamp_difference
-   *  (optional) Timestamp offset, used to mock older or newer files.
+   *  (optional) Timestamp offset, used to mock older or newer files. Defaults
+   *   to zero.
    *
    * @return stdClass
    *   A file object of type stdClass.
@@ -102,7 +103,7 @@ function mockImportedPoFile($langcode, $timestamp_difference = 0) {
   }
 
   /**
-   * Test the basic bulk import functionality.
+   * Tests the basic bulk import functionality of Locale module.
    */
   function testBulkImport() {
     $langcode = 'de';
@@ -126,7 +127,7 @@ function testBulkImport() {
   }
 
   /**
-   * Update a pre-existing file.
+   * Tests the update functionality for a pre-existing file.
    */
   function testBulkImportUpdateExisting() {
     $langcode = 'de';
@@ -157,7 +158,7 @@ function testBulkImportUpdateExisting() {
   }
 
   /**
-   * Don't update a pre-existing file.
+   * Tests the update functionality for a pre-existing file.
    */
   function testBulkImportNotUpdateExisting() {
     $langcode = 'de';
@@ -187,7 +188,7 @@ function testBulkImportNotUpdateExisting() {
   }
 
   /**
-   * Delete translation files after deleting a language.
+   * Tests the deletion of translation files after deleting a language.
    */
   function testDeleteLanguage() {
     $langcode = 'de';
diff --git a/core/modules/locale/lib/Drupal/locale/Tests/LocaleImportFunctionalTest.php b/core/modules/locale/lib/Drupal/locale/Tests/LocaleImportFunctionalTest.php
index 4dca9e7..1b236c0 100644
--- a/core/modules/locale/lib/Drupal/locale/Tests/LocaleImportFunctionalTest.php
+++ b/core/modules/locale/lib/Drupal/locale/Tests/LocaleImportFunctionalTest.php
@@ -31,6 +31,8 @@ public static function getInfo() {
 
   /**
    * A user able to create languages and import translations.
+   *
+   * @var object
    */
   protected $admin_user = NULL;
 
@@ -46,7 +48,7 @@ function setUp() {
   }
 
   /**
-   * Test import of standalone .po files.
+   * Tests the import of stand-alone .po files.
    */
   function testStandalonePoFile() {
     // Try importing a .po file.
@@ -193,7 +195,7 @@ function testStandalonePoFile() {
   }
 
   /**
-   * Test automatic import of a module's translation files.
+   * Tests the automatic import of a module's translation files.
    */
   function testAutomaticModuleTranslationImportLanguageEnable() {
     // Code for the language - manually set to match the test translation file.
@@ -247,7 +249,7 @@ function testAutomaticModuleTranslationImportLanguageEnable() {
   }
 
   /**
-   * Test msgctxt context support.
+   * Tests msgctxt context support.
    */
   function testLanguageContext() {
     // Try importing a .po file.
@@ -260,7 +262,9 @@ function testLanguageContext() {
   }
 
   /**
-   * Test empty msgstr at end of .po file see #611786.
+   * Tests empty msgstr at end of .po file
+   *
+   * see http://drupal.org/node/611786 for more information.
    */
   function testEmptyMsgstr() {
     $langcode = 'hu';
@@ -291,12 +295,13 @@ function testEmptyMsgstr() {
   }
 
   /**
-   * Helper function: import a standalone .po file in a given language.
+   * Imports a standalone .po file in a given language.
    *
    * @param $contents
    *   Contents of the .po file to import.
    * @param $options
-   *   Additional options to pass to the translation import form.
+   *   (optional) Additional options to pass to the translation import form.
+   *   Defaults to an empty array.
    */
   function importPoFile($contents, array $options = array()) {
     $name = tempnam('temporary://', "po_") . '.po';
@@ -307,7 +312,7 @@ function importPoFile($contents, array $options = array()) {
   }
 
   /**
-   * Helper function that returns a proper .po file.
+   * Returns a proper .po file for this test class.
    */
   function getPoFile() {
     return <<< EOF
@@ -348,14 +353,14 @@ function getPoFile() {
   }
 
   /**
-   * Helper function that returns a empty .po file.
+   * Returns an empty .po file for this test class.
    */
   function getEmptyPoFile() {
     return '';
   }
 
   /**
-   * Helper function that returns a bad .po file.
+   * Returns an invalid .po file for this test class.
    */
   function getBadPoFile() {
     return <<< EOF
@@ -380,7 +385,7 @@ function getBadPoFile() {
   }
 
   /**
-   * Helper function that returns a proper .po file for testing.
+   * Returns a proper .po file for testing in this test class.
    */
   function getOverwritePoFile() {
     return <<< EOF
@@ -401,8 +406,7 @@ function getOverwritePoFile() {
   }
 
   /**
-   * Helper function that returns a .po file which strings will be marked
-   * as customized.
+   * Returns a .po file in which some strings are marked as customized.
    */
   function getCustomPoFile() {
     return <<< EOF
@@ -437,7 +441,7 @@ function getCustomPoFile() {
   }
 
   /**
-   * Helper function that returns a .po file for testing customized strings.
+   * Returns a .po file for testing customized strings.
    */
   function getCustomOverwritePoFile() {
     return <<< EOF
@@ -461,7 +465,7 @@ function getCustomOverwritePoFile() {
   }
 
   /**
-   * Helper function that returns a .po file with context.
+   * Returns a .po file with context.
    */
   function getPoFileWithContext() {
     // Croatian (code hr) is one the the languages that have a different
@@ -485,7 +489,7 @@ function getPoFileWithContext() {
   }
 
   /**
-   * Helper function that returns a .po file with an empty last item.
+   * Returns a .po file with an empty last item.
    */
   function getPoFileWithEmptyMsgstr() {
     return <<< EOF
@@ -502,8 +506,9 @@ function getPoFileWithEmptyMsgstr() {
 
 EOF;
   }
+
   /**
-   * Helper function that returns a .po file with an empty last item.
+   * Returns a .po file with a complete last item.
    */
   function getPoFileWithMsgstr() {
     return <<< EOF
diff --git a/core/modules/locale/lib/Drupal/locale/Tests/LocaleInstallTest.php b/core/modules/locale/lib/Drupal/locale/Tests/LocaleInstallTest.php
index fa6aafc..268fb5e 100644
--- a/core/modules/locale/lib/Drupal/locale/Tests/LocaleInstallTest.php
+++ b/core/modules/locale/lib/Drupal/locale/Tests/LocaleInstallTest.php
@@ -37,7 +37,7 @@ function setUp() {
   }
 
   /**
-   * Verify that function signatures of t() and st() are equal.
+   * Verifies that function signatures of t() and st() are equal.
    */
   function testFunctionSignatures() {
     $reflector_t = new ReflectionFunction('t');
diff --git a/core/modules/locale/lib/Drupal/locale/Tests/LocaleJavascriptTranslation.php b/core/modules/locale/lib/Drupal/locale/Tests/LocaleJavascriptTranslation.php
index d8e028f..c120d59 100644
--- a/core/modules/locale/lib/Drupal/locale/Tests/LocaleJavascriptTranslation.php
+++ b/core/modules/locale/lib/Drupal/locale/Tests/LocaleJavascriptTranslation.php
@@ -29,6 +29,9 @@ public static function getInfo() {
     );
   }
 
+  /**
+   * Tests the functionality of parsing translation files with Javascript.
+   */
   function testFileParsing() {
 
     $filename = drupal_get_path('module', 'locale') . '/tests/locale_test.js';
diff --git a/core/modules/locale/lib/Drupal/locale/Tests/LocaleLibraryInfoAlterTest.php b/core/modules/locale/lib/Drupal/locale/Tests/LocaleLibraryInfoAlterTest.php
index 0581124..16bcf49 100644
--- a/core/modules/locale/lib/Drupal/locale/Tests/LocaleLibraryInfoAlterTest.php
+++ b/core/modules/locale/lib/Drupal/locale/Tests/LocaleLibraryInfoAlterTest.php
@@ -31,10 +31,10 @@ public static function getInfo() {
   }
 
   /**
-     * Verifies that the datepicker can be localized.
-     *
-     * @see locale_library_info_alter()
-     */
+   * Verifies that the datepicker can be localized.
+   *
+   * @see locale_library_info_alter()
+   */
   public function testLibraryInfoAlter() {
     drupal_add_library('system', 'jquery.ui.datepicker');
     $scripts = drupal_get_js();
diff --git a/core/modules/locale/lib/Drupal/locale/Tests/LocalePathTest.php b/core/modules/locale/lib/Drupal/locale/Tests/LocalePathTest.php
index d1ad5f0..07155b5 100644
--- a/core/modules/locale/lib/Drupal/locale/Tests/LocalePathTest.php
+++ b/core/modules/locale/lib/Drupal/locale/Tests/LocalePathTest.php
@@ -37,7 +37,7 @@ function setUp() {
   }
 
   /**
-   * Test if a language can be associated with a path alias.
+   * Tests if a language can be associated with a path alias.
    */
   function testPathLanguageConfiguration() {
     global $base_url;
diff --git a/core/modules/locale/lib/Drupal/locale/Tests/LocalePluralFormatTest.php b/core/modules/locale/lib/Drupal/locale/Tests/LocalePluralFormatTest.php
index 8119199..d2e6daf 100644
--- a/core/modules/locale/lib/Drupal/locale/Tests/LocalePluralFormatTest.php
+++ b/core/modules/locale/lib/Drupal/locale/Tests/LocalePluralFormatTest.php
@@ -262,8 +262,9 @@ function testPluralEditExport() {
    *
    * @param $contents
    *   Contents of the .po file to import.
-   * @param $options
-   *   Additional options to pass to the translation import form.
+   * @param array $options
+   *   (optional) Additional options to pass to the translation import form.
+   *   Defaults to an empty array.
    */
   function importPoFile($contents, array $options = array()) {
     $name = tempnam('temporary://', "po_") . '.po';
diff --git a/core/modules/locale/lib/Drupal/locale/Tests/LocaleStringTest.php b/core/modules/locale/lib/Drupal/locale/Tests/LocaleStringTest.php
index 5dd4e23..d07ec13 100644
--- a/core/modules/locale/lib/Drupal/locale/Tests/LocaleStringTest.php
+++ b/core/modules/locale/lib/Drupal/locale/Tests/LocaleStringTest.php
@@ -31,9 +31,6 @@ class LocaleStringTest extends WebTestBase {
    */
   protected $storage;
 
-  /**
-   * @return multitype:string
-   */
   public static function getInfo() {
     return array(
       'name' => 'String storage and objects',
@@ -54,7 +51,7 @@ function setUp() {
   }
 
   /**
-   * Test CRUD API.
+   * Tests the CRUD API functionality.
    */
   function testStringCRUDAPI() {
     // Create source string.
@@ -108,7 +105,7 @@ function testStringCRUDAPI() {
   }
 
   /**
-   * Test Search API loading multiple objects.
+   * Tests the Search API loading multiple objects.
    */
   function testStringSearchAPI() {
     $language_count = 3;
@@ -166,6 +163,13 @@ function testStringSearchAPI() {
 
   /**
    * Creates random source string object.
+   *
+   * @param array $values
+   *   (optional) An array of source string objects.  Defaults to an empty
+   *   array.
+   *
+   * @return object
+   *   A random source string object.
    */
   function buildSourceString($values = array()) {
     return $this->storage->createString($values += array(
@@ -176,6 +180,15 @@ function buildSourceString($values = array()) {
 
   /**
    * Creates translations for source string and all languages.
+   *
+   * @param object $source
+   *   The source string object to be translated into all available languages.
+   * @param array $values
+   *   (optional)  An array of source string objects.  Defaults to an empty
+   *   array.
+   *
+   * @return array
+   *   An array of translations for a source string.
    */
   function createAllTranslations($source, $values = array()) {
     $list = array();
@@ -186,7 +199,15 @@ function createAllTranslations($source, $values = array()) {
   }
 
   /**
-   * Creates single translation for source string.
+   * Creates a single translation for a source string.
+   *
+   * @param object $source
+   *   The source string object to be translated into all available languages.
+   * @param string $langcode
+   *   The language code as a string.
+   * @param array $values
+   *   (optional)  An array of source string objects.  Defaults to an empty
+   *   array.
    */
   function createTranslation($source, $langcode, $values = array()) {
     return $this->storage->createTranslation($values += array(
diff --git a/core/modules/locale/lib/Drupal/locale/Tests/LocaleTranslationTest.php b/core/modules/locale/lib/Drupal/locale/Tests/LocaleTranslationTest.php
index f6ff9c3..32866f5 100644
--- a/core/modules/locale/lib/Drupal/locale/Tests/LocaleTranslationTest.php
+++ b/core/modules/locale/lib/Drupal/locale/Tests/LocaleTranslationTest.php
@@ -41,7 +41,7 @@ function testEnglishTranslation() {
   }
 
   /**
-   * Adds a language and tests string translation by users with the appropriate permissions.
+   * Tests string translation by users with the appropriate permissions.
    */
   function testStringTranslation() {
     global $base_url;
@@ -204,8 +204,10 @@ function testStringTranslation() {
   }
 
   /*
-   * Adds a language and checks that the JavaScript translation files are
-   * properly created and rebuilt on deletion.
+   * Checks the Javascript functionality for creating and rebuild upon deletion.
+   *
+   * This function adds a language and checks that the JavaScript translation
+   * files are properly created and rebuilt on deletion.
    */
   function testJavaScriptTranslation() {
     $user = $this->drupalCreateUser(array('translate interface', 'administer languages', 'access administration pages'));
@@ -322,7 +324,7 @@ function testStringValidation() {
   }
 
   /**
-   * Tests translation search form.
+   * Tests the translation search form.
    */
   function testStringSearch() {
     global $base_url;
diff --git a/core/modules/locale/lib/Drupal/locale/Tests/LocaleUninstallTest.php b/core/modules/locale/lib/Drupal/locale/Tests/LocaleUninstallTest.php
index 06583de..fc1e711 100644
--- a/core/modules/locale/lib/Drupal/locale/Tests/LocaleUninstallTest.php
+++ b/core/modules/locale/lib/Drupal/locale/Tests/LocaleUninstallTest.php
@@ -22,6 +22,13 @@ class LocaleUninstallTest extends WebTestBase {
    */
   public static $modules = array('node', 'locale');
 
+  /**
+   * The default language set for the UI before uninstall.
+   *
+   * @var object
+   */
+  protected $language;
+
   public static function getInfo() {
     return array(
       'name' => 'Locale uninstall (EN)',
@@ -30,11 +37,6 @@ public static function getInfo() {
     );
   }
 
-  /**
-   * The default language set for the UI before uninstall.
-   */
-  protected $language;
-
   function setUp() {
     parent::setUp();
 
@@ -45,7 +47,7 @@ function setUp() {
   }
 
   /**
-   * Check if the values of the Locale variables are correct after uninstall.
+   * Checks if the values of the Locale variables are correct after uninstall.
    */
   function testUninstallProcess() {
     $locale_module = array('locale', 'language');
diff --git a/core/modules/locale/lib/Drupal/locale/TranslationString.php b/core/modules/locale/lib/Drupal/locale/TranslationString.php
index 498dd66..ed13630 100644
--- a/core/modules/locale/lib/Drupal/locale/TranslationString.php
+++ b/core/modules/locale/lib/Drupal/locale/TranslationString.php
@@ -8,7 +8,7 @@
 namespace Drupal\locale;
 
 /**
- * Defines the locale translation string object.
+ * Defines the Locale translation string object.
  *
  * This class represents a translation of a source string to a given language,
  * thus it must have at least a 'language' which is the language code and a
@@ -31,14 +31,14 @@ class TranslationString extends StringBase {
   public $translation;
 
   /**
-   * Integer indicating whether this string is customized.
+   * An integer indicating whether this string is customized.
    *
    * @var int
    */
   public $customized;
 
   /**
-   * Boolean indicating whether the string object is new.
+   * A Boolean indicating whether the string object is new.
    *
    * @var bool
    */
@@ -58,7 +58,7 @@ public function __construct($values = array()) {
   }
 
   /**
-   * Sets the string as customized / not customized.
+   * Marks the string object as customized / not customized.
    *
    * @param bool $customized
    *   (optional) Whether the string is customized or not. Defaults to TRUE.
diff --git a/core/modules/locale/lib/Drupal/locale/TranslationsStream.php b/core/modules/locale/lib/Drupal/locale/TranslationsStream.php
index 3028a32..de92e76 100644
--- a/core/modules/locale/lib/Drupal/locale/TranslationsStream.php
+++ b/core/modules/locale/lib/Drupal/locale/TranslationsStream.php
@@ -26,7 +26,9 @@ function getDirectoryPath() {
 
   /**
    * Implements Drupal\Core\StreamWrapper\StreamWrapperInterface::getExternalUrl().
-   * @throws \LogicException PO files URL should not be public.
+   *
+   * @throws \LogicException
+   *   Throws this exception if the PO files URL should not be public.
    */
   function getExternalUrl() {
     throw new \LogicException('PO files URL should not be public.');
diff --git a/core/modules/locale/locale.admin.css b/core/modules/locale/locale.admin.css
index 2452608..9bd0da2 100644
--- a/core/modules/locale/locale.admin.css
+++ b/core/modules/locale/locale.admin.css
@@ -1,3 +1,8 @@
+/**
+ * @file
+ * Administration styling for the Locale module.
+ */
+
 .locale-translate-filter-form .details-wrapper {
   overflow: hidden;
 }
diff --git a/core/modules/locale/locale.admin.js b/core/modules/locale/locale.admin.js
index a9ded86..4a63b63 100644
--- a/core/modules/locale/locale.admin.js
+++ b/core/modules/locale/locale.admin.js
@@ -1,3 +1,8 @@
+/**
+ * @file
+ * Attaches behaviors for the administrative portion of Locale module.
+ */
+
 (function ($) {
 
 "use strict";
diff --git a/core/modules/locale/locale.batch.inc b/core/modules/locale/locale.batch.inc
index a287e16..c60f7b2 100644
--- a/core/modules/locale/locale.batch.inc
+++ b/core/modules/locale/locale.batch.inc
@@ -2,21 +2,27 @@
 
 /**
  * @file
- *   Batch process to check the availability of remote or local po files.
+ * Batch process to check the availability of remote or local po files.
  */
 
 /**
- * Build a batch to get the status of remote and local translation files.
+ * Builds a batch to get the status of remote and local translation files.
  *
  * The batch process fetches the state of both remote and (if configured) local
  * translation files. The data of the most recent translation is stored per
- * per project and per language. This data is stored in a state variable
+ * project and per language. This data is stored in a state variable
  * 'locale_translation_status'. The timestamp it was last updated is stored
  * in the state variable 'locale_translation_status_last_update'.
  *
  * @param array $sources
  *   Array of translation source objects for which to check the state of
  *   translation source files.
+ *
+ * @return Array
+ *   An associative array with details to retrieve the status of remote and
+ *   local translations files.
+ *
+ * @ingroup batch
  */
 function locale_translation_batch_status_build($sources) {
   $operations = array();
@@ -42,7 +48,7 @@ function locale_translation_batch_status_build($sources) {
 }
 
 /**
- * Batch operation callback: Check the availability of a remote po file.
+ * Batch operation callback: Checks the availability of a remote po file.
  *
  * Checks the presence and creation time of one po file per batch process. The
  * file URL and timestamp are stored.
@@ -76,7 +82,7 @@ function locale_translation_batch_status_fetch_remote($source, &$context) {
 }
 
 /**
- * Batch operation callback: Check the availability of local po files.
+ * Batch operation callback: Checks the availability of local po files.
  *
  * Checks the presence and creation time of po files in the local file system.
  * The file path and the timestamp are stored.
@@ -111,7 +117,7 @@ function locale_translation_batch_status_fetch_local($sources, &$context) {
 }
 
 /**
- * Batch operation callback: Compare states and store the result.
+ * Batch operation callback: Compares states and stores the result.
  *
  * In the preceding batch processes data of remote and local translation sources
  * is collected. Here we compare the collected results and update the source
@@ -151,9 +157,9 @@ function locale_translation_batch_status_compare(&$context) {
 }
 
 /**
- * Batch finished callback: Set result message.
+ * Batch finished callback: Sets result message for translation batch process.
  *
- * @param boolean $success
+ * @param bool $success
  *   TRUE if batch succesfully completed.
  * @param array $results
  *   Batch results.
@@ -175,12 +181,13 @@ function locale_translation_batch_status_finished($success, $results) {
 }
 
 /**
- * Check if remote file exists and when it was last updated.
+ * Checks if remote file exists and when it was last updated.
  *
  * @param string $url
  *   URL of remote file.
  * @param array $headers
- *   HTTP request headers.
+ *   (optional) HTTP request headers. Defaults to an empty array.
+ *
  * @return stdClass
  *   Result object containing the HTTP request headers, response code, headers,
  *   data, redirect status and updated timestamp.
diff --git a/core/modules/locale/locale.bulk.inc b/core/modules/locale/locale.bulk.inc
index d29cf6f..23acadb 100644
--- a/core/modules/locale/locale.bulk.inc
+++ b/core/modules/locale/locale.bulk.inc
@@ -10,10 +10,10 @@
 use Drupal\locale\PoDatabaseReader;
 use Drupal\Core\Language\Language;
 
-
 /**
- * Form constructor for the translation import screen.
+ * Page callback: Form constructor for the translation import screen.
  *
+ * @see locale_menu()
  * @see locale_translate_import_form_submit()
  * @ingroup forms
  */
@@ -138,8 +138,9 @@ function locale_translate_import_form_submit($form, &$form_state) {
 }
 
 /**
- * Form constructor for the Gettext translation files export form.
+ * Page callback: Form constructor for the Gettext translation files export.
  *
+ * @see locale_menu()
  * @see locale_translate_export_form_submit()
  * @ingroup forms
  */
@@ -269,15 +270,17 @@ function locale_translate_export_form_submit($form, &$form_state) {
  *
  * @param array $options
  *   An array with options that can have the following elements:
- *   - 'langcode': The language code, required.
- *   - 'overwrite_options': Overwrite options array as defined in
- *     Drupal\locale\PoDatabaseWriter. Optional, defaults to an empty array.
- *   - 'customized': Flag indicating whether the strings imported from $file
- *     are customized translations or come from a community source. Use
- *     LOCALE_CUSTOMIZED or LOCALE_NOT_CUSTOMIZED. Optional, defaults to
+ *   - langcode: (required) The language code.
+ *   - overwrite_options: (optional) Overwrite options array as defined in
+ *     Drupal\locale\PoDatabaseWriter. Defaults to an empty array.
+ *   - customized: (optional) Flag indicating whether the strings imported from
+ *     $file are customized translations or come from a community source. Use
+ *     LOCALE_CUSTOMIZED or LOCALE_NOT_CUSTOMIZED. Defaults to
  *     LOCALE_NOT_CUSTOMIZED.
- *   - 'finish_feedback': Whether or not to give feedback to the user when the
- *     batch is finished. Optional, defaults to TRUE.
+ *   - finish_feedback: (optional) A Boolean indicating whether or not to give
+ *     feedback to the user when the batch is finished. Defaults to TRUE.
+ *
+ * @ingroup batch
  */
 function locale_translate_add_language_set_batch($options) {
   $options += array(
@@ -293,23 +296,28 @@ function locale_translate_add_language_set_batch($options) {
 }
 
 /**
- * Prepare a batch to import all translations.
+ * Prepares a batch to import all translations.
  *
  * @param array $options
  *   An array with options that can have the following elements:
- *   - 'langcode': The language code. Optional, defaults to NULL, which means
+ *   - langcode: (optional) The language code. Defaults to NULL, which means
  *     that the language will be detected from the name of the files.
- *   - 'overwrite_options': Overwrite options array as defined in
- *     Drupal\locale\PoDatabaseWriter. Optional, defaults to an empty array.
- *   - 'customized': Flag indicating whether the strings imported from $file
- *     are customized translations or come from a community source. Use
- *     LOCALE_CUSTOMIZED or LOCALE_NOT_CUSTOMIZED. Optional, defaults to
+ *   - overwrite_options: (optional) Overwrite options array as defined in
+ *     Drupal\locale\PoDatabaseWriter. Defaults to an empty array.
+ *   - customized: (optional) A flag indicating whether the strings imported
+ *     from $file are customized translations or come from a community source.
+ *     Use LOCALE_CUSTOMIZED or LOCALE_NOT_CUSTOMIZED. Defaults to
  *     LOCALE_NOT_CUSTOMIZED.
- *   - 'finish_feedback': Whether or not to give feedback to the user when the
- *     batch is finished. Optional, defaults to TRUE.
- *
- * @param $force
+ *   - finish_feedback: (optional) A Boolean indicating whether or not to give
+ *     feedback to the user when the batch is finished. Defaults to TRUE.
+ * @param bool $force
  *   (optional) Import all available files, even if they were imported before.
+ *   Defaults to FALSE.
+ *
+ * @return array
+ *   An array with the batch structure details.
+ *
+ * @ingroup batch
  *
  * @todo
  *   Integrate with update status to identify projects needed and integrate
@@ -352,11 +360,11 @@ function locale_translate_batch_import_files($options, $force = FALSE) {
 }
 
 /**
- * Get an array of available interface translation file.
+ * Gets an array of available interface translation files.
  *
- * @param $langcode
- *   The langcode for the interface translation files. Pass NULL to get all
- *   available interface translation files.
+ * @param string|null $langcode
+ *   (optional) The langcode for the interface translation files. Pass NULL to
+ *   get all available interface translation files. Defaults to NULL.
  *
  * @return array
  *   An array of interface translation files.
@@ -374,23 +382,22 @@ function locale_translate_get_interface_translation_files($langcode = NULL) {
 }
 
 /**
- * Build a locale batch from an array of files.
+ * Builds a locale batch from an array of files.
  *
  * @param $files
  *   Array of file objects to import.
- *
  * @param array $options
  *   An array with options that can have the following elements:
- *   - 'langcode': The language code. Optional, defaults to NULL, which means
+ *   - langcode: (optional) The language code. Defaults to NULL, which means
  *     that the language will be detected from the name of the files.
- *   - 'overwrite_options': Overwrite options array as defined in
- *     Drupal\locale\PoDatabaseWriter. Optional, defaults to an empty array.
- *   - 'customized': Flag indicating whether the strings imported from $file
- *     are customized translations or come from a community source. Use
- *     LOCALE_CUSTOMIZED or LOCALE_NOT_CUSTOMIZED. Optional, defaults to
+ *   - overwrite_options: (optiona) Overwrite options array as defined in
+ *     Drupal\locale\PoDatabaseWriter. Defaults to an empty array.
+ *   - customized: (optional) Flag indicating whether the strings imported from
+ *     $file are customized translations or come from a community source. Use
+ *     LOCALE_CUSTOMIZED or LOCALE_NOT_CUSTOMIZED. Defaults to
  *     LOCALE_NOT_CUSTOMIZED.
- *   - 'finish_feedback': Whether or not to give feedback to the user when the
- *     batch is finished. Optional, defaults to TRUE.
+ *   - finish_feedback: (optional) A Boolean indicating whether or not to give
+ *     feedback to the user when the batch is finished. Defaults to TRUE.
  *
  * @return
  *   A batch structure or FALSE if $files was empty.
@@ -424,26 +431,25 @@ function locale_translate_batch_build($files, $options) {
 }
 
 /**
- * Perform interface translation import as a batch step.
+ * Performs interface translation import as a batch step.
  *
  * The given filepath is matched against ending with '{langcode}.po'. When
  * matched the filepath is added to batch context.
  *
  * @param $filepath
  *   Path to a file to import.
- *
  * @param array $options
  *   An array with options that can have the following elements:
- *   - 'langcode': The language code, required.
- *   - 'overwrite_options': Overwrite options array as defined in
- *     Drupal\locale\PoDatabaseWriter. Optional, defaults to an empty array.
- *   - 'customized': Flag indicating whether the strings imported from $file
- *     are customized translations or come from a community source. Use
- *     LOCALE_CUSTOMIZED or LOCALE_NOT_CUSTOMIZED. Optional, defaults to
+ *   - langcode: (required) The language code.
+ *   - overwrite_options: (optional) Overwrite options array as defined in
+ *     Drupal\locale\PoDatabaseWriter. Defaults to an empty array.
+ *   - customized: (optional) Flag indicating whether the strings imported from
+ *     $file are customized translations or come from a community source. Use
+ *     LOCALE_CUSTOMIZED or LOCALE_NOT_CUSTOMIZED. Defaults to
  *     LOCALE_NOT_CUSTOMIZED.
- *
  * @param $context
- *   Contains a list of files imported.
+ *   An array that contains a list of files imported, among other information,
+ *   passed by reference.
  */
 function locale_translate_batch_import($filepath, $options, &$context) {
   // Merge the default values in the $options array.
@@ -517,7 +523,14 @@ function locale_translate_batch_import($filepath, $options, &$context) {
 }
 
 /**
- * Finished callback of system page locale import batch.
+ * Batch completion callback for locale_translate_batch_build().
+ *
+ * @param bool $success
+ *   A Boolean indicating the success status of the batch operation.
+ * @param array $results
+ *   An array with an arbitrary number of batch step results.
+ *
+ * @see locale_translate_batch_import()
  */
 function locale_translate_batch_finished($success, $results) {
   if ($success) {
@@ -580,7 +593,7 @@ function locale_translate_file_create($filepath) {
 }
 
 /**
- * Update the {locale_file} table.
+ * Updates the {locale_file} table.
  *
  * @param $file
  *   Object representing the file just imported.
@@ -606,6 +619,9 @@ function locale_translate_update_file_history($file) {
  *
  * @param $langcode
  *   A langcode or NULL. Pass NULL to delete all interface translation files.
+ *
+ * @return bool
+ *   A Boolean that indicated the success status of the delete files operation.
  */
 function locale_translate_delete_translation_files($langcode) {
   $files = locale_translate_get_interface_translation_files($langcode);
diff --git a/core/modules/locale/locale.bulk.js b/core/modules/locale/locale.bulk.js
index 02cee5e..3fe6ed6 100644
--- a/core/modules/locale/locale.bulk.js
+++ b/core/modules/locale/locale.bulk.js
@@ -1,3 +1,8 @@
+/**
+ * @file
+ * Attaches behaviors for bulk operations portion of Locale module.
+ */
+
 (function ($) {
 
 "use strict";
diff --git a/core/modules/locale/locale.compare.inc b/core/modules/locale/locale.compare.inc
index efe944b..2ceaa8c 100644
--- a/core/modules/locale/locale.compare.inc
+++ b/core/modules/locale/locale.compare.inc
@@ -41,22 +41,22 @@
 use Drupal\Core\Cache;
 
 /**
- * Get array of projects which are available for interface translation.
+ * Gets an array of projects which are available for interface translation.
  *
  * This project data contains all projects which will be checked for available
  * interface translations.
  *
- * For full functionality this function depends on Update module.
- * When Update module is enabled the project data will contain the most recent
- * module status; both in enabled status as in version. When Update module is
- * disabled this function will return the last known module state. The status
- * will only be updated once Update module is enabled.
- *
- * @see locale_translation_build_projects().
+ * For full functionality, this function depends on the Update module. When
+ * Update module is enabled the project data will contain the most recent module
+ * status; both in enabled status as in version. When Update module is disabled
+ * this function will return the last known module state. The status will only
+ * be updated once Update module is enabled.
  *
  * @return array
  *   Array of project data for translation update. See
  *   locale_translation_build_projects() for details.
+ *
+ * @see locale_translation_build_projects().
  */
 function locale_translation_get_projects() {
   $projects = &drupal_static(__FUNCTION__, array());
@@ -82,7 +82,7 @@ function locale_translation_get_projects() {
 }
 
 /**
- * Clear the project data table.
+ * Clears the project data table.
  */
 function locale_translation_flush_projects() {
   db_truncate('locale_project')->execute();
@@ -100,14 +100,14 @@ function locale_translation_flush_projects() {
  *
  * @return array
  *   Array of project data:
- *   - "name": Project system name.
- *   - "project_type": Project type, e.g. 'module', 'theme'.
- *   - "core": Core release version, e.g. 8.x
- *   - "version": Project release version, e.g. 8.x-1.0
+ *   - name: Project system name.
+ *   - project_type: Project type, e.g. 'module', 'theme'.
+ *   - core: Core release version, e.g. 8.x.
+ *   - version: Project release version, e.g. 8.x-1.0.
  *     See http://drupalcode.org/project/drupalorg.git/blob/refs/heads/7.x-3.x:/drupalorg_project/plugins/release_packager/DrupalorgProjectPackageRelease.class.php#l219
  *     for how the version strings are created.
- *   - "server_pattern": Translation server po file pattern.
- *   - "status": Project status, 1 = enabled.
+ *   - server_pattern: Translation server po file pattern.
+ *   - status: Project status, 1 = enabled.
  */
 function locale_translation_build_projects() {
   // This function depends on Update module. We degrade gracefully.
@@ -187,7 +187,7 @@ function locale_translation_build_projects() {
 }
 
 /**
- * Fetch an array of projects for translation update.
+ * Fetches an array of projects for translation update.
  *
  * @return array
  *   Array of project data including .info file data.
@@ -224,7 +224,7 @@ function locale_translation_project_list() {
 }
 
 /**
- * Prepare module and theme data.
+ * Prepares module and theme data.
  *
  * Modify .info file data before it is processed by update_process_info_list().
  * In order for update_process_info_list() to recognize a project, it requires
@@ -238,7 +238,7 @@ function locale_translation_project_list() {
  * @param array $data
  *   Array of .info file data.
  * @param string $type
- *   The project type. i.e. module, theme.
+ *   The project type. e.g. 'module', or 'theme'.
  *
  * @return array
  *   Array of .info file data.
@@ -256,11 +256,11 @@ function _locale_translation_prepare_project_list($data, $type) {
 }
 
 /**
- * Retrieve data for default server.
+ * Retrieves data for default server.
  *
  * @return array
  *   Array of server parameters:
- *   - "server_pattern": URL containing po file pattern.
+ *   - server_pattern: URL containing po file pattern.
  */
 function locale_translation_default_translation_server() {
   $config = config('locale.settings');
@@ -270,16 +270,16 @@ function locale_translation_default_translation_server() {
 }
 
 /**
- * Build path to translation source, out of a server path replacement pattern.
+ * Builds path to translation source, out of a server path replacement pattern.
  *
  * @param stdClass $project
  *   Project object containing data to be inserted in the template.
  * @param string $template
  *   String containing placeholders. Available placeholders:
- *   - "%project": Project name.
- *   - "%version": Project version.
- *   - "%core": Project core version.
- *   - "%language": Language code.
+ *   - %project: Project name.
+ *   - %version: Project version.
+ *   - %core: Project core version.
+ *   - %language: Language code.
  *
  * @return string
  *   String with replaced placeholders.
@@ -295,12 +295,13 @@ function locale_translation_build_server_pattern($project, $template) {
 }
 
 /**
- * Check for the latest release of project translations.
+ * Checks for the latest release of project translations.
  *
  * @param array $projects
- *   Projects to check (objects).
- * @param string $langcodes
- *   Array of language codes to check for. Leave empty to check all languages.
+ *   An array of Projects (objects) to check.
+ * @param array|null $langcodes
+ *   (optional) Array of language codes to check for. Leave empty to check all
+ *   languages. Defaults to NULL.
  *
  * @return array
  *   Available sources indexed by project and language.
@@ -329,8 +330,11 @@ function locale_translation_check_projects($projects, $langcodes = NULL) {
  *
  * @params array $projects
  *   Array of translatable projects.
- * @params array $langcodes
- *   Array of language codes to check for. Leave empty to check all languages.
+ * @params array|null $langcodes
+ *   (optional) Array of language codes to check for. Leave empty to check all
+ *   languages. Defaults to NULL.
+ *
+ * @ingroup batch
  */
 function locale_translation_check_projects_batch($projects, $langcodes = NULL) {
   $langcodes = $langcodes ? $langcodes : array_keys(locale_translatable_language_list());
@@ -349,7 +353,7 @@ function locale_translation_check_projects_batch($projects, $langcodes = NULL) {
 }
 
 /**
- * Check and store the status and timestamp of local po files.
+ * Checks and stores the status and timestamp of local po files.
  *
  * Only po files in the local file system are checked. Any remote translation
  * sources will be ignored. Results are stored in the state variable
@@ -363,8 +367,9 @@ function locale_translation_check_projects_batch($projects, $langcodes = NULL) {
  *
  * @params array $projects
  *   Array of translatable projects.
- * @params array $langcodes
- *   Array of language codes to check for. Leave empty to check all languages.
+ * @params array|null $langcodes
+ *   (optional) Array of language codes to check for. Leave empty to check all
+ *   languages. Defaults to NULL.
  */
 function locale_translation_check_projects_local($projects, $langcodes = NULL) {
   $langcodes = $langcodes ? $langcodes : array_keys(locale_translatable_language_list());
@@ -389,7 +394,7 @@ function locale_translation_check_projects_local($projects, $langcodes = NULL) {
 }
 
 /**
- * Check whether a po file exists in the local filesystem.
+ * Checks whether a po file exists in the local filesystem.
  *
  * It will search in the directory set in the translation source. Which defaults
  * to the "translations://" stream wrapper path. The directory may contain any
@@ -403,15 +408,16 @@ function locale_translation_check_projects_local($projects, $langcodes = NULL) {
  *
  * @param stdClass $source
  *   Translation source object.
- *   @see locale_translation_source_build()
  *
  * @return stdClass
  *   File object (filename, basename, name) updated with data of the po file.
  *   On success the files property of the source object is updated.
  *   files['local']:
- *   - "uri": File name and path.
- *   - "timestamp": Last updated time of the po file.
- *   FALSE if the file is not found.
+ *   - uri: File name and path.
+ *   - timestamp: Last updated time of the po file.
+ *   A Boolean FALSE is returned if the file is not found.
+ *
+ * @see locale_translation_source_build()
  */
 function locale_translation_source_check_file(&$source) {
   if (isset($source->files['local'])) {
@@ -436,36 +442,37 @@ function locale_translation_source_check_file(&$source) {
 }
 
 /**
- * Build abstract translation source.
+ * Builds abstract translation source.
  *
  * @param stdClass $project
  *   Project object.
  * @param string $langcode
  *   Language code.
- * @param string $filename
- *   File name of translation file. May contains placeholders.
+ * @param string|null $filename
+ *   (optional) File name of translation file. This string may contain
+ *   placeholders. Defaults to NULL.
  *
  * @return object
  *   Source object:
- *   - "project": Project name.
- *   - "name": Project name (inherited from project).
- *   - "language": Language code.
- *   - "core": Core version (inherited from project).
- *   - "version": Project version (inherited from project).
- *   - "project_type": Project type (inherited from project).
- *   - "files": Array of file objects containing properties of local and remote
+ *   - project: Project name.
+ *   - name: Project name (inherited from project).
+ *   - language: Language code.
+ *   - core: Core version (inherited from project).
+ *   - version: Project version (inherited from project).
+ *   - project_type: Project type (inherited from project).
+ *   - files: Array of file objects containing properties of local and remote
  *     translation files.
  *   Other processes can add the following properties:
- *   - "type": Most recent file type 'remote' or 'local'. Corresponding with
- *     a key of the "files" array.
- *   - "timestamp": Timestamp of the most recent translation file.
- *   The "files" array contains file objects with the following properties:
- *   - "uri": Local file path.
- *   - "url": Remote file URL for downloads.
- *   - "directory": Directory of the local po file.
- *   - "filename": File name.
- *   - "timestamp": Timestamp of the file.
- *   - "keep": TRUE to keep the downloaded file.
+ *   - type: Most recent file type 'remote' or 'local'. Corresponding with a key
+ *     of the 'files' array.
+ *   - timestamp: Timestamp of the most recent translation file.
+ *   The 'files' array contains file objects with the following properties:
+ *   - uri: Local file path.
+ *   - url: Remote file URL for downloads.
+ *   - directory: Directory of the local po file.
+ *   - filename: File name.
+ *   - timestamp: Timestamp of the file.
+ *   - keep: TRUE to keep the downloaded file.
  */
 // @todo Move this file?
 function locale_translation_source_build($project, $langcode, $filename = NULL) {
@@ -508,13 +515,13 @@ function locale_translation_source_build($project, $langcode, $filename = NULL)
 }
 
 /**
- * Determine if a file is a remote file.
+ * Determines if a file is a remote file.
  *
  * @param string $url
  *   The URL or URL pattern of the file.
  *
- * @return boolean
- *   TRUE if the $url is a remote file.
+ * @return bool
+ *   TRUE if the $url is a remote file; otherwise, FALSE.
  */
 function _locale_translation_file_is_remote($url) {
   $scheme = file_uri_scheme($url);
@@ -525,7 +532,7 @@ function _locale_translation_file_is_remote($url) {
 }
 
 /**
- * Compare two update sources, looking for the newer one.
+ * Compares two update sources, looking for the newer one.
  *
  * The timestamp property of the source objects are used to determine which is
  * the newer one.
@@ -536,12 +543,12 @@ function _locale_translation_file_is_remote($url) {
  *   Source object of available update.
  *
  * @return integer
- *   - "LOCALE_TRANSLATION_SOURCE_COMPARE_LT": $source1 < $source2 OR $source1
- *     is missing.
- *   - "LOCALE_TRANSLATION_SOURCE_COMPARE_EQ":  $source1 == $source2 OR both
+ *   - LOCALE_TRANSLATION_SOURCE_COMPARE_LT: $source1 < $source2 OR $source1 is
+ *     missing.
+ *   - LOCALE_TRANSLATION_SOURCE_COMPARE_EQ: $source1 == $source2 OR both
  *     $source1 and $source2 are missing.
- *   - "LOCALE_TRANSLATION_SOURCE_COMPARE_GT":  $source1 > $source2 OR $source2
- *     is missing.
+ *   - LOCALE_TRANSLATION_SOURCE_COMPARE_GT: $source1 > $source2 OR $source2 is
+ *     missing.
  */
 function _locale_translation_source_compare($source1, $source2) {
   if (isset($source1->timestamp) && isset($source2->timestamp)) {
diff --git a/core/modules/locale/locale.install b/core/modules/locale/locale.install
index f01935a..a9531f2 100644
--- a/core/modules/locale/locale.install
+++ b/core/modules/locale/locale.install
@@ -258,7 +258,7 @@ function locale_schema() {
  */
 
 /**
- * Drops textgroup support.
+ * Drop textgroup support.
  *
  * Update assumes i18n migrated this data before the update happened. Core never
  * used textgroups for anything, so it is not our job to find a place for the
@@ -335,7 +335,7 @@ function locale_update_8001() {
 }
 
 /**
- * Removes duplicates in {locales_source}.
+ * Remove duplicates in {locales_source}.
  *
  * Aggressively removes duplicates that has not already been removed by
  * locale_update_7004() in Drupal 7.x.
@@ -365,7 +365,7 @@ function locale_update_8002() {
 }
 
 /**
- * Converts language domains to new format.
+ * Convert language domains to new format.
  *
  * @ingroup config_upgrade
  */
@@ -759,7 +759,7 @@ function locale_update_8011() {
 }
 
 /**
- * Renames language_default language negotiation method to language_selected.
+ * Rename language_default language negotiation method to language_selected.
  */
 function locale_update_8013() {
   $weight = update_variable_get('language_negotiation_methods_weight_language_interface', NULL);
diff --git a/core/modules/locale/locale.module b/core/modules/locale/locale.module
index 85ed5d1..91444c6 100644
--- a/core/modules/locale/locale.module
+++ b/core/modules/locale/locale.module
@@ -2,7 +2,7 @@
 
 /**
  * @file
- * Enables the translation of the user interface to languages other than English.
+ * Enables translation of the user interface to languages other than English.
  *
  * When enabled, multiple languages can be set up. The site interface can be
  * displayed in different languages, and nodes can have languages assigned. The
@@ -295,14 +295,17 @@ function locale_translatable_language_list() {
  *
  * This function is called from t() to translate a string if needed.
  *
- * @param $string
- *   A string to look up translation for. If omitted, all the
- *   cached strings will be returned in all languages already
- *   used on the page.
- * @param $context
- *   The context of this string.
- * @param $langcode
- *   Language code to use for the lookup.
+ * @param string|null $string
+ *   (optional) A string to look up translation for. If omitted, all the cached
+ *   strings will be returned in all languages already used on the page.
+ *   Defaults to NULL.
+ * @param string|null $context
+ *   (optional) The context of this string. Defaults to NULL.
+ * @param string|null $langcode
+ *   (optional) Language code to use for the lookup. Defaults to NULL.
+ *
+ * @return string
+ *   Either the translated string or the original string.
  */
 function locale($string = NULL, $context = NULL, $langcode = NULL) {
   $language_interface = language(LANGUAGE_TYPE_INTERFACE);
@@ -343,7 +346,7 @@ function locale($string = NULL, $context = NULL, $langcode = NULL) {
 }
 
 /**
- * Reset static variables used by locale().
+ * Resets static variables used by locale().
  */
 function locale_reset() {
   drupal_static_reset('locale');
@@ -353,6 +356,7 @@ function locale_reset() {
  * Gets the locale storage controller class .
  *
  * @return Drupal\locale\StringStorageInterface
+ *   A new instance of a StringStorageInterface class.
  */
 function locale_storage() {
   $storage = &drupal_static(__FUNCTION__);
@@ -371,8 +375,9 @@ function locale_storage() {
  * @param $count
  *   Number to return plural for.
  * @param $langcode
- *   Optional language code to translate to a language other than
- *   what is used to display the page.
+ *   (optional) The language code to translate to a language other than what is
+ *   used to display the page. Defaults to NULL.
+ *
  * @return
  *   The numeric index of the plural variant to use for this $langcode and
  *   $count combination or -1 if the language was not found or does not have a
@@ -415,7 +420,6 @@ function locale_get_plural($count, $langcode = NULL) {
   return $plural_indexes[$langcode][$count];
 }
 
-
 /**
  * Implements hook_modules_installed().
  */
@@ -443,6 +447,8 @@ function locale_themes_enabled($themes) {
  *   An array of component (theme and/or module) names to import
  *   translations for.
  *
+ * @ingroup batch
+ *
  * @todo
  *   This currently imports all .po files available, independent of
  *   $components. Once we integrated with update status for project
@@ -690,7 +696,9 @@ function locale_translate_english() {
 /**
  * Implements hook_form_FORM_ID_alter() for system_file_system_settings().
  *
- * Add interface translation directory setting to directories configuration.
+ * Adds interface translation directory setting to directories configuration.
+ *
+ * @see locale_system_file_system_settings_submit()
  */
 function locale_form_system_file_system_settings_alter(&$form, $form_state) {
   $form['locale_translate_file_directory'] = array(
@@ -723,6 +731,10 @@ function locale_system_file_system_settings_submit(&$form, $form_state) {
 
 /**
  * Implements hook_preprocess_HOOK() for node.tpl.php.
+ *
+ * @param array $variables
+ *   An associative array with the following key:
+ *   - langcode
  */
 function locale_preprocess_node(&$variables) {
   if ($variables['node']->langcode != LANGUAGE_NOT_SPECIFIED) {
@@ -753,7 +765,7 @@ function locale_translation_clear_status() {
 }
 
 /**
- * Check that a string is safe to be added or imported as a translation.
+ * Checks that a string is safe to be added or imported as a translation.
  *
  * This test can be used to detect possibly bad translation strings. It should
  * not have any false positives. But it is only a test, not a transformation,
@@ -765,6 +777,13 @@ function locale_translation_clear_status() {
  * The allowed tag list is like filter_xss_admin(), but omitting div and img as
  * not needed for translation and likely to cause layout issues (div) or a
  * possible attack vector (img).
+ *
+ * @param string $string
+ *   A text string to be checked for its 'safe' status.'
+ *
+ * @return bool
+ *   A Boolean TRUE indicating that the string is safe to be added or imported
+ *   as a translation; otherwise, FALSE.
  */
 function locale_string_is_safe($string) {
   return decode_entities($string) == decode_entities(filter_xss($string, array('a', 'abbr', 'acronym', 'address', 'b', 'bdo', 'big', 'blockquote', 'br', 'caption', 'cite', 'code', 'col', 'colgroup', 'dd', 'del', 'dfn', 'dl', 'dt', 'em', 'h1', 'h2', 'h3', 'h4', 'h5', 'h6', 'hr', 'i', 'ins', 'kbd', 'li', 'ol', 'p', 'pre', 'q', 'samp', 'small', 'span', 'strong', 'sub', 'sup', 'table', 'tbody', 'td', 'tfoot', 'th', 'thead', 'tr', 'tt', 'ul', 'var')));
@@ -794,8 +813,10 @@ function _locale_refresh_translations($langcodes, $lids) {
 }
 
 /**
- * Parses a JavaScript file, extracts strings wrapped in Drupal.t() and
- * Drupal.formatPlural() and inserts them into the database.
+ * Parses a Javascript file and adds the extracted string to the database.
+ *
+ * This function parses a JavaScript file, extracts strings wrapped in
+ * Drupal.t() and Drupal.formatPlural() and inserts them into the database.
  *
  * @param string $filepath
  *   File name to parse.
@@ -902,15 +923,16 @@ function _locale_parse_js_file($filepath) {
 }
 
 /**
- * Force the JavaScript translation file(s) to be refreshed.
+ * Forces the JavaScript translation file(s) to be refreshed.
  *
  * This function sets a refresh flag for a specified language, or all
  * languages except English, if none specified. JavaScript translation
  * files are rebuilt (with locale_update_js_files()) the next time a
  * request is served in that language.
  *
- * @param $langcode
- *   The language code for which the file needs to be refreshed.
+ * @param string|null $langcode
+ *   (optional) The language code for which the file needs to be refreshed.
+ *   Defaults to NULL.
  *
  * @return
  *   New content of the 'system.javascript_parsed' variable.
@@ -937,8 +959,12 @@ function _locale_invalidate_js($langcode = NULL) {
 /**
  * (Re-)Creates the JavaScript translation file for a language.
  *
- * @param $langcode
- *   The language, the translation file should be (re)created for.
+ * @param string|null $langcode
+ *   (optional) The language, the translation file should be (re)created for.
+ *   Defaults to NULL.
+ *
+ * @return bool
+ *   TRUE indicates the desired operation was successful; otherwise, FALSE.
  */
 function _locale_rebuild_js($langcode = NULL) {
   if (!isset($langcode)) {
diff --git a/core/modules/locale/locale.pages.inc b/core/modules/locale/locale.pages.inc
index 72f1793..0e9dc2e 100644
--- a/core/modules/locale/locale.pages.inc
+++ b/core/modules/locale/locale.pages.inc
@@ -12,6 +12,9 @@
 /**
  * Page callback: Shows the string search screen.
  *
+ * @return array
+ *   A form array suitable for a call to drupal_render().
+ *
  * @see locale_menu()
  */
 function locale_translate_page() {
@@ -25,7 +28,7 @@ function locale_translate_page() {
  * Builds a string search query and returns an array of string objects.
  *
  * @return array
- *   Array of Drupal\locale\TranslationString objects.
+ *   Array of \Drupal\locale\TranslationString objects.
  */
 function locale_translate_filter_load_strings() {
   $filter_values = locale_translate_filter_values();
@@ -61,7 +64,10 @@ function locale_translate_filter_load_strings() {
 }
 
 /**
- * Build array out of search criteria specified in request variables.
+ * Builds array out of search criteria specified in request variables.
+ *
+ * @return array
+ *   A filtered list of translation values.
  */
 function locale_translate_filter_values() {
   $filter_values = &drupal_static(__FUNCTION__);
@@ -91,7 +97,10 @@ function locale_translate_filter_values() {
 }
 
 /**
- * List locale translation filters that can be applied.
+ * Lists locale translation filters that can be applied.
+ *
+ * @return array
+ *   An array of translation filters that are available.
  */
 function locale_translate_filters() {
   $filters = array();
@@ -154,7 +163,9 @@ function locale_translate_filters() {
 }
 
 /**
- * Return form for locale translation filters.
+ * Form constructor for locale translation filters form.
+ *
+ * @see locale_translate_filter_form_submit()
  *
  * @ingroup forms
  */
@@ -218,7 +229,7 @@ function locale_translate_filter_form($form, &$form_state) {
 }
 
 /**
- * Process result from locale translation filter form.
+ * Form submissiion handler for locale_translate_filter_form().
  */
 function locale_translate_filter_form_submit($form, &$form_state) {
   $op = $form_state['values']['op'];
@@ -244,7 +255,6 @@ function locale_translate_filter_form_submit($form, &$form_state) {
 /**
  * Form constructor for the string editing form.
  *
- * @see locale_menu()
  * @see locale_translate_edit_form_validate()
  * @see locale_translate_edit_form_submit()
  *
@@ -446,7 +456,7 @@ function locale_translate_edit_form_submit($form, &$form_state) {
 }
 
 /**
- * Page callback: Checks for translation updates and displays the translations status.
+ * Page callback: Checks for translation updates and displays the status.
  *
  * Manually checks the translation status without the use of cron.
  *
@@ -469,6 +479,9 @@ function locale_translation_manual_status() {
 /**
  * Page callback: Display the current translation status.
  *
+ * @return string
+ *   A string that summarizes the current translation status.
+ *
  * @see locale_menu()
  */
 function locale_translation_status() {
@@ -483,7 +496,13 @@ function locale_translation_status() {
 }
 
 /**
- * Default theme function for translation edit form.
+ * Returns HTML for the translation edit form.
+ *
+ * @param array $variables
+ *   An associative array containing the following key:
+ *   - form: The form definition array.
+ *
+ * @ingroup themeable
  */
 function theme_locale_translate_edit_form_strings($variables) {
   $output = '';
diff --git a/core/modules/locale/tests/modules/locale_test/locale_test.module b/core/modules/locale/tests/modules/locale_test/locale_test.module
index 03e455d..bc43a48 100644
--- a/core/modules/locale/tests/modules/locale_test/locale_test.module
+++ b/core/modules/locale/tests/modules/locale_test/locale_test.module
@@ -2,7 +2,7 @@
 
 /**
  * @file
- * Simulate a custom module with a local po file.
+ * Simulates a custom module with a local po file.
  */
 
 /**