diff --git a/core/modules/locale/lib/Drupal/locale/Tests/LocaleCompareTest.php b/core/modules/locale/lib/Drupal/locale/Tests/LocaleCompareTest.php
index 1f176bf..d4c448f 100644
--- a/core/modules/locale/lib/Drupal/locale/Tests/LocaleCompareTest.php
+++ b/core/modules/locale/lib/Drupal/locale/Tests/LocaleCompareTest.php
@@ -36,6 +36,12 @@ 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');
@@ -75,7 +81,7 @@ private function makePoFile($path, $filename, $timestamp = NULL, $data = '') {
     $po_header = <<<EOF
 msgid ""
 msgstr ""
-"Project-Id-Version: Drupal 7\\n"
+"Project-Id-Version: Drupal 8\\n"
 "MIME-Version: 1.0\\n"
 "Content-Type: text/plain; charset=UTF-8\\n"
 "Content-Transfer-Encoding: 8bit\\n"
@@ -152,8 +158,8 @@ function testLocaleCompare() {
    * Normally remote files are located at a remote server (e.g. ftp.drupal.org).
    * For testing we can not rely on this. A directory in the file system of the
    * test site is designated for remote files and is addressed using an absolute
-   * URL. Because drupal does not allow file with a po extension to be accessed
-   * (denied in .htaccess) the translation files  get a txt extension. An other
+   * URL. Because drupal does not allow files with a po extension to be accessed
+   * (denied in .htaccess) the translation files get a txt extension. An other
    * directory is designated for local translation files.
    *
    * The translation status process by default checks the status of the
@@ -176,8 +182,8 @@ function testCompareCheckLocal() {
     state()->set('locale_translation_test_projects', TRUE);
 
     // Setup timestamps to identify old and new translation sources.
-    $timestamp_old =  REQUEST_TIME - 100;
-    $timestamp_new =  REQUEST_TIME;
+    $timestamp_old = REQUEST_TIME - 100;
+    $timestamp_new = REQUEST_TIME;
 
     // Setup the environment.
     $public_path = variable_get('file_public_path', conf_path() . '/files');
@@ -192,15 +198,12 @@ function testCompareCheckLocal() {
     $this->makePoFile('remote/8.x/contrib_module_three', 'contrib_module_three-8.x-1.0.de.txt', $timestamp_old);
 
     // Add a number of files to the local file system to serve as local
-    // translation files and match the projct definitions set in
+    // translation files and match the project definitions set in
     // locale_test_locale_translation_projects_alter().
     $this->makePoFile('local', 'contrib_module_one-8.x-1.1.de.txt', $timestamp_old);
     $this->makePoFile('local', 'contrib_module_two-8.x-2.0-beta4.de.txt', $timestamp_new);
     $this->makePoFile('local', 'custom_module_one.de.po', $timestamp_new);
 
-    //debug(file_scan_directory(variable_get('file_public_path', conf_path() . '/files') . '/local', '/.*\.*/', array('recurse' => TRUE)));
-    //debug(file_scan_directory(variable_get('file_public_path', conf_path() . '/files') . '/remote', '/.*\.*/', array('recurse' => TRUE)));
-
     // Get status of translation sources at local file system.
     $config->set('translation.check_mode', LOCALE_TRANSLATION_CHECK_LOCAL)->save();
     $this->drupalGet('admin/reports/translations/check');
@@ -223,6 +226,6 @@ function testCompareCheckLocal() {
     $this->assertEqual($result['contrib_module_three']['de']->type, 'remote', 'Translation of contrib_module_three found');
     $this->assertEqual($result['contrib_module_three']['de']->timestamp, $timestamp_old, 'Translation timestamp found');
     $this->assertEqual($result['locale_test']['de']->type, 'local', 'Translation of locale_test found');
-    $this->assertEqual($result['custom_module_one']['de']->type, 'local', 'Translation of custom_module_one. found');
+    $this->assertEqual($result['custom_module_one']['de']->type, 'local', 'Translation of custom_module_one found');
   }
 }
diff --git a/core/modules/locale/locale.api.php b/core/modules/locale/locale.api.php
index ea1085f..5005018 100644
--- a/core/modules/locale/locale.api.php
+++ b/core/modules/locale/locale.api.php
@@ -28,7 +28,7 @@
  * the module's folder.
  * @code
  * interface translation project = example_module
- * interface translation server pattern = sites/all/modules/custom/example_module/%project-%version.%language.po
+ * interface translation server pattern = modules/custom/example_module/%project-%version.%language.po
  * @endcode
  *
  * Streamwrappers can be used in the server pattern definition. The interface
diff --git a/core/modules/locale/locale.batch.inc b/core/modules/locale/locale.batch.inc
index 1e659fc..92c998d 100644
--- a/core/modules/locale/locale.batch.inc
+++ b/core/modules/locale/locale.batch.inc
@@ -2,7 +2,7 @@
 
 /**
  * @file
- *   Batch proces to check the availability of remote Gettext .po files.
+ *   Batch process to check the availability of remote or local po files.
  */
 
 /**
@@ -10,7 +10,7 @@
  *
  * 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 a state variable
+ * per 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'.
  *
@@ -53,6 +53,9 @@ function locale_translation_batch_status_build($sources) {
  * @param array $context
  *   The batch context array. The collected state is stored in the 'results'
  *   parameter of the context.
+ *
+ * @see locale_translation_batch_status_fetch_local()
+ * @see locale_translation_batch_status_compare()
 */
 function locale_translation_batch_status_fetch_remote($source, &$context) {
   // Check the translation file at the remote server and update the source
@@ -62,7 +65,7 @@ function locale_translation_batch_status_fetch_remote($source, &$context) {
     $result = locale_translation_http_check($remote_file->url);
 
     // Update the file object with the result data. In case of a redirect we
-    // we store the resulting url.
+    // store the resulting url.
     if ($result && !empty($result->updated)) {
       $remote_file->url = isset($result->redirect_url) ? $result->redirect_url : $remote_file->url;
       $remote_file->timestamp = $result->updated;
@@ -84,6 +87,9 @@ function locale_translation_batch_status_fetch_remote($source, &$context) {
  * @param array $context
  *   The batch context array. The collected state is stored in the 'results'
  *   parameter of the context.
+ *
+ * @see locale_translation_batch_status_fetch_remote()
+ * @see locale_translation_batch_status_compare()
  */
 function locale_translation_batch_status_fetch_local($sources, &$context) {
   module_load_include('compare.inc', 'locale');
@@ -116,6 +122,9 @@ function locale_translation_batch_status_fetch_local($sources, &$context) {
  * @param array $context
  *   The batch context array. The 'results' element contains a structured array
  *   of project data with languages, local and remote source data.
+ *
+ * @see locale_translation_batch_status_fetch_remote()
+ * @see locale_translation_batch_status_fetch_local()
  */
 function locale_translation_batch_status_compare(&$context) {
   module_load_include('compare.inc', 'locale');
diff --git a/core/modules/locale/locale.compare.inc b/core/modules/locale/locale.compare.inc
index 8df171b..99506d2 100644
--- a/core/modules/locale/locale.compare.inc
+++ b/core/modules/locale/locale.compare.inc
@@ -313,8 +313,7 @@ function locale_translation_check_projects_batch($projects, $langcodes = NULL) {
   $sources = array();
   foreach ($projects as $name => $project) {
     foreach ($langcodes as $langcode) {
-      $project_clone = clone $project;
-      $source = locale_translation_source_build($project_clone, $langcode);
+      $source = locale_translation_source_build($project, $langcode);
       $sources[] = $source;
     }
   }
@@ -328,7 +327,7 @@ function locale_translation_check_projects_batch($projects, $langcodes = NULL) {
 /**
  * Check and store the status and timestamp of local po files.
  *
- * Only po files in the local file system and checked. Any remote translation
+ * Only po files in the local file system are checked. Any remote translation
  * sources will be ignored. Results are stored in the state variable
  * 'locale_translation_status'.
  *
@@ -395,8 +394,9 @@ function locale_translation_source_check_file(&$source) {
     $directory = $source->files['local']->directory;
     $filename = '/' . preg_quote($source->files['local']->filename) . '$/';
 
-    // If the directory contains a streamwrapper, it is converted to a real
-    // path.
+    // If the directory contains a stream wrapper, it is converted to a real
+    // path. This is required for file_scan_directory() which can not handle
+    // stream wrappers.
     if ($scheme = file_uri_scheme($directory)) {
       $directory = str_replace($scheme . '://', drupal_realpath($scheme . '://'), $directory);
     }
@@ -445,6 +445,7 @@ function locale_translation_source_check_file(&$source) {
  */
 // @todo Move this file?
 function locale_translation_source_build($project, $langcode, $filename = NULL) {
+  // Create a source object with data of the project object.
   $source = clone $project;
   $source->project = $project->name;
   $source->language = $langcode;
@@ -483,13 +484,13 @@ function locale_translation_source_build($project, $langcode, $filename = NULL)
 }
 
 /**
- * Determine if the source file is a remote or a local file.
+ * Determine 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 location.
+ *   TRUE if the $url is a remote file.
  */
 function _locale_translation_file_is_remote($url) {
   $scheme = file_uri_scheme($url);
@@ -515,7 +516,6 @@ function _locale_translation_file_is_remote($url) {
  *   - "0":  $source1 == $source2 OR both $source1 and $source2 are missing.
  *   - "1":  $source1 > $source2 OR $source2 is missing.
  */
-// @todo Move to locale.inc?
 function _locale_translation_source_compare($source1, $source2) {
   if (isset($source1->timestamp) && isset($source2->timestamp)) {
     if (abs($source1->timestamp - $source2->timestamp) < LOCALE_TRANSLATION_TIMESTAMP_THRESHOLD) {
diff --git a/core/modules/locale/locale.pages.inc b/core/modules/locale/locale.pages.inc
index 3fe1968..37495cf 100644
--- a/core/modules/locale/locale.pages.inc
+++ b/core/modules/locale/locale.pages.inc
@@ -463,22 +463,22 @@ function locale_translation_manual_status() {
 
 /**
  * Page callback: Display the current translation status.
+ *
+ * @see locale_menu()
  */
 function locale_translation_status() {
   $languages = locale_translatable_language_list();
   if (!$languages) {
-    drupal_set_message(t('No translatable languages available. <a href="@add_lanuage">Add a language</a> first.', array('@add_lanuage' => url('admin/config/regional/language'))), 'warning');
+    drupal_set_message(t('No translatable languages available.') . ' ' . l(t('Add language'), 'admin/config/regional/language'), 'warning');
   }
 
-//debug(state()->get('locale_translation_status'));
-//debug(format_date(state()->get('locale_translation_status_last_update'), 'long'));
-
-  // @todo Calculate and display the translation status here.
-  return 'TODO: Show the transaltion status here';
+  // @todo Calculate and display the translation status here. See the follow-up
+  // issue for translation interface: http://drupal.org/node/1804702
+  return 'TODO: Show the translation status here';
 }
 
 /**
- * Default theme function for translatione edit form.
+ * Default theme function for translation edit form.
  */
 function theme_locale_translate_edit_form_strings($variables) {
   $output = '';
diff --git a/core/modules/locale/tests/modules/locale_test/locale_test.module b/core/modules/locale/tests/modules/locale_test/locale_test.module
index c22e307..03e455d 100644
--- a/core/modules/locale/tests/modules/locale_test/locale_test.module
+++ b/core/modules/locale/tests/modules/locale_test/locale_test.module
@@ -18,7 +18,7 @@ function locale_test_system_info_alter(&$info, $file, $type) {
   // test modules should mimic a custom module. I.e. be non-hidden.
   if (state()->get('locale_translation_test_system_info_alter')) {
     if ($file->name == 'locale_test' || $file->name == 'locale_test_disabled') {
-      // Make the module appear as unhidden.
+      // Don't hide the module.
       $info['hidden'] = FALSE;
     }
   }