diff --git a/core/modules/tracker/tracker.install b/core/modules/tracker/tracker.install
index cfe8dc7..6d2d317 100644
--- a/core/modules/tracker/tracker.install
+++ b/core/modules/tracker/tracker.install
@@ -1,6 +1,11 @@
 <?php
 
 /**
+ * @file
+ * Install, update, and uninstall functions for tracker.module.
+ */
+
+/**
  * Implements hook_uninstall().
  */
 function tracker_uninstall() {
diff --git a/core/modules/tracker/tracker.module b/core/modules/tracker/tracker.module
index 227cf72..e053199 100644
--- a/core/modules/tracker/tracker.module
+++ b/core/modules/tracker/tracker.module
@@ -2,7 +2,7 @@
 
 /**
  * @file
- * Enables tracking of recent content for users.
+ * Tracks recent content posted by a user or users.
  */
 
 /**
@@ -70,6 +70,11 @@ function tracker_menu() {
 
 /**
  * Implements hook_cron().
+ *
+ * Updates tracking information for any items still to be tracked. The variable
+ * 'tracker_index_nid' is set to ((the last nid that was indexed) - 1) and used
+ * to select the nodes to be processed. If there are no remaining nodes to
+ * process, 'tracker_index_nid' will be 0.
  */
 function tracker_cron() {
   $max_nid = variable_get('tracker_index_nid', 0);
@@ -148,7 +153,17 @@ function tracker_cron() {
 }
 
 /**
- * Access callback for tracker/%user_uid_optional.
+ * Access callback: Determines access permission for a user's own account.
+ *
+ * Callback path: tracker/%user_uid_optional
+ *
+ * @param int $account
+ *   The account ID to check.
+ * @return boolean
+ *   Return TRUE if a user is accessing tracking info for their own account
+ *   and has permission to access the content.
+ *
+ * @see tracker_menu()
  */
 function _tracker_myrecent_access($account) {
   // This path is only allowed for authenticated users looking at their own content.
@@ -156,7 +171,17 @@ function _tracker_myrecent_access($account) {
 }
 
 /**
- * Access callback for user/%user/track.
+ * Access callback: Determines access permission for an account.
+ *
+ * Callback path: user/%user/track
+ *
+ * @param int $account
+ *   The user account ID to track.
+ * @return boolean
+ *   Returns TRUE if a user has permission to access the account for $account
+ *   and has permission to access the content.
+ *
+ * @see tracker_menu()
  */
 function _tracker_user_access($account) {
   return user_view_access($account) && user_access('access content');
@@ -164,6 +189,8 @@ function _tracker_user_access($account) {
 
 /**
  * Implements hook_node_insert().
+ *
+ * Adds new tracking information for this node since it's new.
  */
 function tracker_node_insert($node, $arg = 0) {
   _tracker_add($node->nid, $node->uid, $node->changed);
@@ -171,6 +198,8 @@ function tracker_node_insert($node, $arg = 0) {
 
 /**
  * Implements hook_node_update().
+ *
+ * Adds tracking information for this node since it's been updated.
  */
 function tracker_node_update($node, $arg = 0) {
   _tracker_add($node->nid, $node->uid, $node->changed);
@@ -178,6 +207,8 @@ function tracker_node_update($node, $arg = 0) {
 
 /**
  * Implements hook_node_delete().
+ *
+ * Deletes tracking information for a node.
  */
 function tracker_node_delete($node, $arg = 0) {
   db_delete('tracker_node')
@@ -227,7 +258,7 @@ function tracker_comment_delete($comment) {
 }
 
 /**
- * Update indexing tables when a node is added, updated or commented on.
+ * Updates indexing tables when a node is added, updated or commented on.
  *
  * @param $nid
  *   A node ID.
@@ -266,7 +297,7 @@ function _tracker_add($nid, $uid, $changed) {
 }
 
 /**
- * Determine the max timestamp between $node->changed and the last comment.
+ * Determines the max timestamp between $node->changed and the last comment.
  *
  * @param $nid
  *   A node ID.
@@ -288,7 +319,7 @@ function _tracker_calculate_changed($nid) {
 }
 
 /**
- * Clean up indexed data when nodes or comments are removed.
+ * Cleans up indexed data when nodes or comments are removed.
  *
  * @param $nid
  *  The node ID.
diff --git a/core/modules/tracker/tracker.pages.inc b/core/modules/tracker/tracker.pages.inc
index 7b1e946..91df2b2 100644
--- a/core/modules/tracker/tracker.pages.inc
+++ b/core/modules/tracker/tracker.pages.inc
@@ -2,12 +2,20 @@
 
 /**
  * @file
- * User page callbacks for the tracker module.
+ * User page callbacks for tracker.module.
  */
 
 
 /**
- * Menu callback; prints a listing of active nodes on the site.
+ * Page callback: Generates a page of tracked nodes for the site.
+ *
+ * Queries the database for info, adds RDFa info if applicable, and generates
+ * the render array that will be used to render the page.
+ *
+ * @return array
+ *   A renderable array to be themed in page_theme().
+ *
+ * @see tracker_menu()
  */
 function tracker_page($account = NULL, $set_title = FALSE) {
   if ($account) {
diff --git a/core/modules/tracker/tracker.test b/core/modules/tracker/tracker.test
index 3cc227e..7e5467d 100644
--- a/core/modules/tracker/tracker.test
+++ b/core/modules/tracker/tracker.test
@@ -5,11 +5,30 @@
  * Tests for tracker.module.
  */
 
+/**
+ * Defines a base class for testing tracker.module.
+ */
 class TrackerTest extends DrupalWebTestCase {
+
+  /**
+   * The main user for testing. Information should be correct for this user.
+   *
+   * @var object
+   */
   protected $user;
+
+  /**
+   * A second user that will 'create' comments and nodes.
+   *
+   * @var object
+   */
   protected $other_user;
+
   protected $new_node;
 
+  /**
+   * Overrides DrupalWebTestCase::getInfo().
+   */
   public static function getInfo() {
     return array(
       'name' => 'Tracker',
@@ -18,6 +37,10 @@ class TrackerTest extends DrupalWebTestCase {
     );
   }
 
+  /**
+   * Overrides DrupalWebTestCase::setUp().
+   *
+   */
   function setUp() {
     parent::setUp('comment', 'tracker');
 
@@ -30,7 +53,7 @@ class TrackerTest extends DrupalWebTestCase {
   }
 
   /**
-   * Test the presence of nodes on the global tracker listing.
+   * Tests for the presence of nodes on the global tracker listing.
    */
   function testTrackerAll() {
     $this->drupalLogin($this->user);
@@ -56,7 +79,7 @@ class TrackerTest extends DrupalWebTestCase {
   }
 
   /**
-   * Test the presence of nodes on a user's tracker listing.
+   * Tests for the presence of nodes on a user's tracker listing.
    */
   function testTrackerUser() {
     $this->drupalLogin($this->user);
@@ -102,7 +125,7 @@ class TrackerTest extends DrupalWebTestCase {
   }
 
   /**
-   * Test the presence of the "new" flag for nodes.
+   * Tests for the presence of the "new" flag for nodes.
    */
   function testTrackerNewNodes() {
     $this->drupalLogin($this->user);
@@ -130,7 +153,7 @@ class TrackerTest extends DrupalWebTestCase {
   }
 
   /**
-   * Test comment counters on the tracker listing.
+   * Tests for comment counters on the tracker listing.
    */
   function testTrackerNewComments() {
     $this->drupalLogin($this->user);
@@ -168,7 +191,7 @@ class TrackerTest extends DrupalWebTestCase {
   }
 
   /**
-   * Test that existing nodes are indexed by cron.
+   * Tests that existing nodes are indexed by cron.
    */
   function testTrackerCronIndexing() {
     $this->drupalLogin($this->user);
@@ -226,7 +249,7 @@ class TrackerTest extends DrupalWebTestCase {
   }
 
   /**
-   * Test that publish/unpublish works at admin/content/node
+   * Tests that publish/unpublish works at admin/content/node.
    */
   function testTrackerAdminUnpublish() {
     $admin_user = $this->drupalCreateUser(array('access content overview', 'administer nodes', 'bypass node access'));